William Tuttle came to Freeport in 1797 to farm potatoes, but his deadly combination of clear-cutting and overgrazing caused enough erosion to expose the glacial desert hidden beneath the topsoil. The shifting dunes, which are 90ft deep in some areas, cover entire trees and the old farm's buildings. Admission includes a 30-minute tram tour and lots of kiddie attractions, such as gemstone hunting and a butterfly room.