The largest spring on the St Johns River, Blue Spring maintains a constant 72°F. Between November and March it becomes the winter refuge for up to 200 West Indian manatees. The best time to see them is before 11am; there's a wheelchair-accessible path to the viewing platform. This tranquil state park is a revitalizing spot to swim (prohibited when manatees are present), snorkel or canoe.
Campsites ($24), basic cabins ($95) and gear rentals are available.
You can also spend two hours cruising the peaceful waters with St Johns River Cruises, whose nature tours offer a thoughtful insight into this fragile ecosystem.