Blue Hole Mineral Spring

Located off a beaten path in a remote part of Jamaica, this spot is a popular attraction that remains open until the early hours of the morning when the last person leaves.

With the surface of the chilly water 25 feet below the land, visitors either dive in or climb down a ladder. It's another 30 feet to the bottom. The cavernous opening is completely encased in Karst limestone, a naturally occurring mineral that filters the steady upwelling of water, leaving behind a clear, clean pool. 

The mud around the pool is also said to be great for the skin, and the water is valued for its mineral properties. And if you're not brave enough to climb in, well, there's a pool with the water from the hole pumped up to higher ground.