About The Birch Wathen Lenox School. Since 1916, BWL, a K–12, coeducational, college preparatory independent school, has stood out on the Upper East Side of Manhattan as one of the most close-knit institutions the big city has to offer its most promising young people. Inside our unassuming brownstone building is a beyond-supportive community of experienced educators and devoted families who are committed to a mission of fostering growth and celeb...