Rainbow Springs, a first-magnitude artesian spring several miles north of Dunnellon, is the source of the Rainbow River and the fourth-largest spring in Florida, releasing more than 490 million gallons of water daily. Known earlier to the Seminole as Wekiwa Creek and later as Blue Spring, it was renamed in the 1930s as it developed into a tourist attraction. In the mid-20th century it drew visitors with submarine tours and mermaid shows, but after the attraction closed in the 1970s, its natural importance came to the forefront. Protected designations followed, and in 1990 the State of Florida purchased the headwaters, helping preserve the site as Rainbow Springs State Park.