9. The Noble and Greenough School

Dedham, Mass.

Tuition and boarding: $56,000

This school offers a program where about 85 percent of students study abroad before graduating. The school is co-ed and emphasizes experiential and community learning and is partnered with more than 400 work sites worldwide, according to the school’s mission statement. Notable alumni include former President John F. Kennedy and astronomer Percival Lowell, according to a report from Forbes.