The University of Florida, located at the heart of historic Gainesville, has a major impact on the city. The University Art Gallery and Teaching Hall is the center of the art community. The College of Medicine is an important and impressive presence here. However, academia, culture and a youthful population are only some of the factors that contribute to the character of Gainesville. The North-Eastern Historical District preserves 63 blocks containing no less than 290 historic buildings of various architectural styles, dating from 1880 to 1920. Ancient natural history can be explored at Devil's Millhopper State Geological Site, where visitors can descend 232 steps into a 20-million-year-old sinkhole, or at Lake Alice Wildlife Preserve on the edge of the University Campus. Wild horses, descended from those brought over by the Spanish settlers, reside at the Pains Prairie State Preserve. The Florida Museum of Natural History, with two sites on the University of Florida Campus, preserves 25,000,000 specimens. Overlooking Lake Kanapaha, the Lake Kanapaha Botanical Gardens is an environmentally diverse site with 10 major gardens and a 29-acre arboretum. Just five minutes from famous Suwannee River is the Shady Groves Eco Ranch, a 240-acre park with seven miles of trails.