Both are worth a trip, but they suit different travelers. Here is the honest side-by-side to help you choose — or fit both into one route.
They sit about 1 miles apart, which makes doing both in one trip realistic. Here is how they actually differ.
| Devil's Den | Blue Grotto Dive Resort | |
|---|---|---|
| Our score | 8.5 / 10 | 7.8 / 10 |
| Entry fee | ~$18 / person (reservation) | ~$30 / diver (verify) |
| Hours | By reservation | By reservation |
| Magnitude | Subterranean spring | Karst sink/cavern |
| Nearest town | Williston | Williston |
| Best for | The most otherworldly swim in Florida | Florida's clearest training cavern — divers only |
| Good for | Scuba Diving, Snorkeling | Scuba Diving, Snorkeling |
| When to go | ||
| Current conditions | Open · reservations required, weekends selling out | Open · reservations required |
Devil's Den
Devil's Den is a prehistoric spring inside a collapsed limestone cave — you descend a wooden staircase into the earth and surface-swim beneath a skylight fringed with hanging vines while sun rays cut through the water. There is nothing else like it in Florida, and the…
Local tip: Book the first morning slot: fewest swimmers, best light rays, clearest water. Water is 72°F in a shaded cave — a thin wetsuit (rentable) makes the visit far more comfortable.
Full guide, fees & map →Blue Grotto Dive Resort
Two minutes from Devil's Den, Blue Grotto is the serious sibling: a 100-foot-deep cavern with famously clear water, a permanent air bell 30 feet down, and platforms that make it the state's favorite dive-training site. This one is for divers — swimmers should book Devil's Den…
Local tip: Book alongside Devil's Den for a two-site Williston dive day. Midweek mornings get the glassiest water.
Full guide, fees & map →