In 1894, Dr. Cyrus Reed Teed and 200 of his religious followers came to Estero from New York to build a tabernacle for their faith, Koreshanity. Known as the Koreshan Unity, they believed the universe existed inside a large, hollow sphere. They carried out an elaborate series of survey experiments, trying to prove that the horizons on Lee County beaches actually curve upward but when Teed died in 1908, his religion began fading out. The last four members of the faith deeded 100 acres of their land to the State of Florida in 1961.

Today, you can either follow a ranger on a guided tour of the property (on the weekends) or engage in the self-guided version (any time). You can also hike, picnic, boat and fish, too. The park also offers a boat ramp and canoe rentals and has a full-facility campground that offers campfire programs evey Friday evening from January through March.

Koreshan State Historic Site is located at the intersection of US Highway 41 and Corkscrew Road. The park is open for day use from 8 am to sunset, every day of the year. Admission fees: $4 per single occupant vehicle, $5 per vehicle to a max of 8 occupants, $2 for pedestrians, bicyclists and extra passengers. Camping fees: $26 (plus tax) per site per night. The guided tours run $2 per adult, $1 per child. In addition to the entrance fees, use of the boat ramp costs $4 per boat and use of the RV dump station costs $10 for non-campers. Canoe rentals run $5 (plus tax) per hour to a max of $25 (plus tax) per day.

Koreshan State Historic Site is listed on the National Register of Historic Places as Koreshan Unity Settlement Historic District.