Silver Springs is a group of artesian springs that feed into the Silver River in Marion County, Florida. It is the largest artesian spring in the world and the site of the oldest commercial tourist attraction in Florida, and was designated a National Natural Landmark in 1971. Its main features are the glass-bottom boat tours on the river, which have operated there, in various forms, since 1878. Long privately owned and operated, the springs area was formerly the site of a small amusement park, Silver Springs Nature Theme Park.