2023-2024 Admissions: Léman is accepting applications for Explorers (12-24 months) to Grade 12. Submit your application today on Ravenna.

Questions? Contact admissions@lemanmanhattan.org We look forward to meeting your family!

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About Léman

Leadership & Faculty

Instructional excellence is a foundational pillar of the Léman experience. As a team of educators, our goal is to ignite children's passion for learning through superior teaching. Through one-on-one, small group, and differentiated instruction, our faculty members know and appreciate each student's unique interests, strengths, goals, and learning styles.

In addition to our nurturing and accomplished faculty, more than 80% of whom possess advanced degrees and credentials, Léman benefits from the expertise of experienced administrators and department chairs. We approach our practice with a shared mission: to help every child grow and succeed, and to build a community of the highest caliber teaching.

Our Teachers

Léman teachers do not simply provide superior instruction — our teachers lead, inspire, excite and relate to students in a caring, supportive manner.

We place intense focus on every child's learning experience, encouraging curiosity, accomplishment, and growth. Teachers at every grade level ensure that students engage deeply in content, build critical thinking skills, make connections between their work and the world, and enhance their skills to the greatest extent of their aptitudes and abilities.

Our team of educators is highly collaborative, working in grade level, department, and cross-curricular teams to cultivate best practice teaching methodologies and ensure curriculum is vertically articulated across grades to support each student's continuous growth. Léman teachers create nurturing, inclusive learning environments and teach to each child's interest and ability level every day, in each lesson, to achieve progress benchmarked to individual goals.

Léman teachers are energetic professionals who care deeply about their students and their own professional growth. They participate in professional development opportunities for continuous improvement throughout the year and are committed to honing their craft to enable our students to benefit from innovative educational practices. Léman teachers do not simply provide superior instruction, they lead and inspire students in a caring, supportive manner to help them realize their full potential.


Maria Castelluccio

Head of School

Ms. Castelluccio was named Head of School at Léman Manhattan in October 2015 and began her term in July 2016. A proven educational leader and visionary, Ms. Castelluccio has dedicated her career to driving student performance and building community in PreK-12 schools in the U.S. and internationally for more than 25 years. She joins Léman after four years as the Head of School at Marymount International School of Rome, also an International Baccalaureate School, where she developed and carried out a strategic plan that increased IB scores to 98% pass rate and 45% of students scoring in the top 20th percentile worldwide.

From 2009-2012, Ms. Castelluccio served as Marymount Rome's Elementary School Principal, where her accomplishments included introducing Columbia University Teachers College Reader's and Writer's Workshop and Responsive Classroom, and advancing the academic rigor of the educational program. For more than a decade prior to Marymount Rome, Ms. Castelluccio held senior administrative roles at high-performing elementary schools in Westport and Stratford, Connecticut. She began her career as a 3rd and 4th Grade teacher. Ms. Castelluccio holds a Bachelor of Arts in Intermediate Education, Magna Cum Laude, from Southern Connecticut State University; a Master of Science in Science Education from Southern Connecticut State University; and a Sixth Year Degree in Administration and Supervision from Sacred Heart University. Originally from the Bronx, Maria raised her four children in Fairfield County, Connecticut. She is an avid reader, and when she has the time, loves to travel, walk and practice yoga.

Maria Sweeney

Director of Curriculum

Mrs. Sweeney serves as the academic dean for PreK-12th grade, working closely with the academic division heads to further develop and implement curriculum consistent with our school mission, vision, core values and IB philosophy. Mrs. Sweeney joined Léman from Oakhill Academy in Temecula, CA, where she was Head of School from 2015-2019. Previously, Mrs. Sweeney was the Curriculum Coordinator PreK-12 and then the Early Childhood and Elementary Principal at the Marymount International School of Rome from 2007-2015. For more than 25 years before joining Marymount, Mrs. Sweeney served as an administrator and classroom and ESOL teacher in schools across the world. Mrs. Sweeney holds the following educational credentials: Bachelor's Degree in Psychology from Loyola Marymount University in Los Angeles; Teaching Certificate from University of California, Los Angeles; Master's Degree in Curriculum and Instruction from University of California, Riverside; Post-Master's ESL Certificate in English as a Second Language from Eastern University, St. David's; and Principal's Certificate in Educational Leadership from The Principal's Training Center. Outside of Léman, Mrs. Sweeney likes to read, cook, travel and spend time with her family. Her daughter is a graduate of Léman’s Class of 2021.

Sabah Rashid

Head of The Center for Early Childhood Education & Lower School

Ms. Rashid oversees the academic program for Léman’s youngest students in Explorers (12-24 months old) to 5th grade. She is an experienced international educator with nearly 20 years teaching and leadership experience in International Baccalaureate (IB) schools. Ms. Rashid joined Léman from Saint Andrew’s School in Boca Raton, FL, a leading PreK-12 day and boarding school, where she served as the IB Primary Years Programme (PYP) Coordinator.

From 2014 to 2019, Ms. Rashid served as the Founding Head of Primary School at Swiss International Scientific School in Dubai, UAE. Since 2012, Ms. Rashid has served as a consultant and evaluator of IB Schools as part of the International Baccalaureate Educator Network. Prior to working at Swiss International, Sabah was the PYP Coordinator and taught as a classroom teacher in grades 3 and 5, also in Dubai. Sabah holds a Certification in School Management and Leadership from Harvard Graduate School of Education and Harvard Business School, a Master of Arts in Elementary and Secondary Teaching from University of California Irvine, and a Bachelor of Arts in International Studies from the University of California Irvine.

Eric Hawthorn

Head of Middle School

In his role as Head of Middle School, Mr. Hawthorn has a focus on working with middle school students (grades 6-8), and serves on the upper school leadership team to build community across grades 6 through 12, spearhead new initiatives and special projects, and develop programming that supports students academically, socially and emotionally.

Mr. Hawthorn joined Léman in Fall 2014 and taught both Middle School and High School Social Studies and launched a new Student Ambassador program. After one academic year, he was promoted to the Assistant Head position. Prior to joining Léman, Mr. Hawthorn taught Social Studies, P.E, and Health in charter and private schools in the New York City area. Originally from the U.K., Mr. Hawthorn holds a B.A. in Education with a specialization in History and Physical Education. Outside of school, Mr. Hawthorn enjoys exercising, reading, watching and coaching soccer, listening to music, and spending time with his three godchildren.

Dr. Harry Leonardatos

Head of High School

Dr. Leonardatos oversees the academic program for grades 9-12 at Léman, and is an experienced high school administrator and teacher with more than 30 years in leadership and faculty roles. Previously, Dr. Leonardatos was High School Principal of Clarkstown High School North, a 1,300 student IB World School, in New City, NY. During his career, he has received numerous recognitions for his work, including the Distinguished Doctoral Dissertation Award from SUNY Albany and the Clarkstown Lifetime Achievement Award.

Shortly after becoming principal of Clarkstown in 2005, Dr. Leonardatos introduced and implemented the IB Diploma Program there. Prior to being named principal, Dr. Leonardatos spent two years as a teacher and social studies chairperson. Previously, he was Principal of American Greek Institute in NYC, a PreK-8 school. From 1990-2001, Dr. Leonardatos was a teacher at Archbishop Molloy School in Queens, NY, one of the most highly rated private Catholic high schools in the New York area. Dr. Leonardatos began his teaching career at the Greek American Institute in 1987. He holds a Ph.D. in Educational Administration Policy Studies from SUNY at Albany, a Professional Diploma in School Administration from The College of New Rochelle, a Master of Arts in Teaching from Fordham University, a Master of Arts in Political Science from The New School, and a Bachelor of Arts in Political Science and Philosophy from Fordham University. He is a lifelong New Yorker and attended NYC independent schools. Dr. Leonardatos is fluent in Greek and proficient in Spanish.

Luz Garcelon

Director of International Baccalaureate (IB) Programming

Luz Garcelon joined Léman in 2021 from the United Nations International School (UNIS) in Manhattan, where she served as the IB Diploma Coordinator since 2015. At UNIS, Ms. Garcelon supervised the IB program to promote academic success, oversaw the organization of IB exams and evaluations, coordinated teacher professional development and partnered closely with parents and administration to support student achievement. During this time, she also served as a Spanish teacher for grades 6-12. From 2011 to 2015, she held other leadership roles at UNIS including Student Engagement Team Leader and UNIS-UN Faculty Advisor.

Prior to UNIS, Ms. Garcelon led the IB program as IB Program Coordinator at Santiago College School in Santiago, Chile, an IB World School serving students in preschool through grade 12. She began her education career at Santiago College School as an English Teacher, where she instructed higher level and standard English classes to prepare students for IB external and internal assessments.

Quinn Greene

Director of Student Support Services

Ms. Greene oversees Léman’s team of learning support specialists, school counselors and nursing professionals to support the academic and overall well-being of Léman students. As a staunch advocate for educational equity, Ms. Greene has spent over a decade utilizing her voice and knowledge of special education and disability studies to create inclusive school communities in a variety of settings. Ms. Greene left her role as an Analyst in the financial sector in 2012 to earn her M.S. in Teaching Urban Adolescents with Disabilities from Long Island University. As an educator in New York public schools, Quinn developed Advanced Placement curriculum and taught English and U.S. Government in grades 9-12.

After three years in the Department of Education, Quinn joined Uncommon Schools as a Special Education Coordinator where she also coached Learning Specialists and led humanities courses for students with disabilities in grades 9-12. During her tenure at Uncommon Collegiate, Quinn developed an Academic Support Program which, to date, has assisted over 200 students who were at risk for retention in graduating and going on to college. Quinn's most recent role as the Dean of Special Services at Achievement First Crown Heights Charter School was multi-faceted. There, she designed and implemented the school's Co-Teaching vision, coached, and developed the school's social work team and Learning Specialists, and spearheaded the Child Study Team with a focus on Tier II and III behavior intervention. When not at work, Quinn enjoys volunteering in therapeutic horsemanship and cheering on her Rutgers University Scarlet Knights!

Lisa Nowicki

Director of Fine Arts

Ms. Nowicki oversees all curricular and extra-curricular programs in Visual Arts, Music, Theatre, and Film for Léman Manhattan. Prior to coming to Léman in 2011, Ms. Nowicki served as the Performing Arts Department Chair at the Sanford School in Hockessin, DE, where she worked for 19 years and produced award-winning music ensembles and a nationally recognized Theatre program. In Theatre, Ms. Nowicki has worked as a musical director, producer, and conductor. She is the co-founder of Delaware All-State Theatre®, the nation's only All-State Theatre organization for students, and serves on their Board of Trustees. In addition, she is a former chairperson of the DAIS Music Educators group, which involves 23 schools in DE, PA, MD, and NJ. Outside of education, Ms. Nowicki has worked in corporate arts administration and has served as an Associate Producer for “Lisa Howard: Songs of Innocence & Experience, The Songs of William Finn” (Ghostlight/Sh-K-Boom Records). Ms. Nowicki received a B.S. in Music Education from West Chester University and a Masters in Educational Psychology from Widener University. She has graduate credits in music history from the University of Salzburg in Salzburg, Austria. Apart from her interests in music, theatre, and film, she enjoys reading, baking, and travel.

Keith Sequeira

Director of Athletics

Keith Sequeira leads athletic opportunities for students school-wide at Léman, including team sports in grade five, to elite level varsity sports at the high school level. During his time at Léman, Mr. Sequeira has grown the athletic program significantly, from 8 teams in 2009, when he joined the school, to 36 teams today. In his leadership of the athletic program at Léman, Mr. Sequeira builds a culture of community, sportsmanship and physical well-being across the school community. Mr. Sequeira brings a wealth of knowledge of New York City school athletic programs, from his Adjunct Professor position at St. Francis College in Brooklyn, as well as his positions as Athletic Director, Physical Education Chair, Admissions Director, Summer Camp and After School Director at schools in New York and New Jersey. Mr. Sequeira earned a B.A. in Physical Education from Hofstra University and a Masters in supervision from Adelphi University. Outside of his duties at Léman, Mr. Sequeira is on the board of the Old Bridge Girls Soccer League, where his daughters participate in the soccer program. He enjoys quality time with his wife and two daughters, as well as the most recent addition to their family, "Bubba" the mini pincher.

Dennis Vasquez

Director of College Counseling

Mr. Vasquez is the Director of College Counseling. After earning his B.A. in Psychology at Boston College in 1996, Mr. Vasquez was also commissioned in the U.S. Army and served on active duty. After reaching the rank of Captain, he decided to find work in the civilian world, following his passion with helping high school students pursue their dreams. His first job was as an admissions officer at Skidmore College, then switched to college counseling positions since 2003. Mr. Vasquez worked at Newark Academy, Livingston High School, and then at a non-profit organization, The Student Leadership Network/The Collegebound Initiative, as a supervisor of a team of college counselors at multiple high schools located throughout New York City. He has a Master's in Business Administration and has presented on various workshops on college counseling and financial aid at both the regional (NYSACAC) and national (NACAC) level and has done private consulting work in college access for families coming from a range of cultural and socio-economic backgrounds.

Outside of Léman, Mr. Vasquez enjoys spending time with his wife, an administrator for the NYC Department of Education and all his children. Mr. Vasquez is Filipino and enjoys learning to speak Spanish, traveling, playing a variety of musical instruments, boxing, and tennis.

Brandon Miller

Upper School Dean of Students

In his role as Dean of Students, Mr. Miller supports Léman’s school culture by working closely with Upper School students and faculty. He oversees student clubs, activities, and trips. In addition, Mr. Miller manages the planning, logistics and scheduling of Léman’s Advisory Program, which fosters an inclusive learning environment, social and emotional learning and strong self-management and study skills.

Prior to Léman, Mr. Miller served as a student dean for nine years at schools in the New York City area. Most recently, he was the Founding Dean of School Culture at Achievement First Ujima High School. Mr. Miller’s 17-year career in education spans curriculum development, data analysis, school operations, lesson planning, teacher supervision and support, and program development. Mr. Miller earned his B.A. in History and Secondary Education from SUNY College at Old Westbury.

Scott Thompson

Chief Operating Officer

Scott Thompson leads the business office, facilities and technology teams to help support our school's continued innovation and growth. An experienced finance and strategy executive in the education industry, Mr. Thompson has held various executive leadership and chief financial officer roles both domestically and internationally and has also served on numerous boards of directors. He holds a BA in Accounting from University of Wisconsin-Whitewater and a Global Executive MBA from the Fuqua School of Business at Duke University. Mr. Thompson lives in Lower Manhattan with his wife Laurie and son Sloane, who is a Léman high school student.

Ahsan Karim

Director of Technology

Mr. Karim oversees all aspects of educational technology at Léman and drives the school's strategic vision for leveraging technology to enhance student learning. He has oversight for all technology systems that support student information, enrollment management, scheduling and grading, faculty collaboration, parent communication, and the cultivation of technology skills that prepare Léman students for an interconnected, digital world.

An IT professional with over two decades of experience in educational technology and technology support, Mr. Karim brings many years of teaching and administrative experience to our school. Prior to joining Léman, Mr. Karim spent 25 years at The Buckley School on the Upper East Side, where he managed all hardware, software, systems, and infrastructure initiatives, including the implementation of makerspaces. He also has extensive experience in developing and leading technology professional development workshops for faculty and staff. Throughout his career, he has taught coding, robotics, and circuit building in grades 1-9.

Mr. Karim holds a bachelor's degree in Computer Science from The College of Staten Island. He is a Google Certified Educator and also a Microsoft Certified Systems Engineer. He lives with his wife and daughter in Forest Hills, Queens, and during his free time, Mr. Karim enjoys cooking, reading and traveling with his family.

Steve Levin

Director of After-School and Summer Programs

With over 20 years of experience developing children's programming in New York City, Steve Levin leads Léman's after school and summer programs. With a broad array of offerings ranging from chess to math club to tennis, our after school programming complements the Léman academic program to harness the interest of every child. In addition, Camp Léman, for both Léman students and children in the community, is one of Lower Manhattan's premier programs for children, enrolling over 270 children each summer. Prior to joining Léman in 2008, Mr. Levin served as the Director of Camp Programs at the 92nd Street Y, and as camp director in the Poconos. Mr. Levin spent four years on the adjunct faculty of Fordham University's Graduate school of Social Service and has been a speaker and co-chair for various regional and national camping conferences. Mr. Levin has a B.A. in Psychology from Northwestern University and a Masters in Social Work from Hunter College. Outside of his work at Léman, Mr. Levin enjoys travel, running, exploring New York City, and the New York Times crossword puzzle. He currently lives in Brooklyn with his wife and two daughters who are both students at Léman.

Paige Murphy

Head of Communications & Enrollment Management

Mrs. Murphy oversees the admissions and communications functions at Léman. She partners with faculty, students and parents to build a dynamic and engaged community of Léman families and share student accomplishments and school developments within Léman and beyond. Since joining Léman in 2014, Mrs. Murphy has led Léman’s strategic enrollment growth and raised Léman’s visibility to attract a talented and diverse applicant pool and ultimately enrolled students who thrive in Léman’s IB program.

Mrs. Murphy joined Léman after more than 15 years in K-12 and higher education senior communications roles. Prior to Léman, Mrs. Murphy was Executive Director of Marketing for Kaplan, the global educational services provider. Previously, she was an Assistant Director of Communications at Columbia University.

Mrs. Murphy holds a B.A. in Political Science and French from Colgate University. She lives in the Financial District with her husband and two sons, who are students in Léman’s Lower School. Outside of school, Mrs. Murphy enjoys tennis, travel, and architecture.

Joshua Anchors

Director of Global Admissions and Residential Life

Joshua Anchors collaborates with the school's partners from around the world to bring talented, motivated international students to Léman Manhattan. As the director of Léman's unique boarding program, Mr. Anchors is also responsible for the academic and socio-emotional well-being of 120 students from over 20 different countries. Originally from Maine, Mr. Anchors worked in disaster relief for a variety of organizations including the United Nations, FEMA, and the Louisiana Recovery Authority, before transitioning into education. Prior to working at Léman Manhattan, he taught at Saint Ann's School, the Brooks School, University Laval, and the University of Strasbourg. Mr. Anchors holds degrees from Columbia University, Boston University, and the University of Maine. Outside of his work at Léman, he enjoys bicycling, sea kayaking, and creative writing.

Debbie Aragon

Head of Human Resources

Debbie Aragón leads the Human Resources Department at Léman by leading benefits analysis and administration, compensation, staff training & development, workers’ compensation, safety training, employee relations, performance management, organizational development, and HRIS. Ms. Aragón has over 15 years in human resource management and prior to Léman was Head of Human Resources at TAO Group, VP of HR at Dean & Deluca, Director of HR at Max Brenner, and the US HR Administration Manager at Le Pain Quotidien. She holds a Bachelor of Arts degree in Psychology from Hofstra University, a Human Resources accreditation from Pace University and is a member of the Society for Human Resource Management (SHRM). A Queens native, she currently lives on Long Island with her three children and two Persian cats and enjoys crafts, yoga, and spending time on the beach with her family in the summer.

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