At Sudbury Valley School, students from *preschool through high school age* explore the world freely, at their own pace and in their own unique ways.
http://sudval.org/

Applicants must be *at least four years old*
http://sudval.org/01_abou_06.html

The school is governed on the model of a traditional New England Town Meeting. The daily affairs of the school are managed by the weekly School Meeting, at which each student and staff member has one vote. Rules of behavior, use of facilities, expenditures, staff hiring, and all the routines of running an institution are determined by debate and vote at the School Meeting. At Sudbury Valley, students share fully the responsibility for effective operation of the school and for the quality of life at school.
http://sudval.org/01_abou_05.html