The Venetian Pool in Coral Gables is an old rock quarry that was built into a public pool and is filled with new water from an underground aquifer each day. But don't fear the environmental implications: the water is drained back into the aquifer, where it can cycle through the filtration process naturally and sustainably. The coral rock structures form beautiful waterfalls and grottos, making this one of the most popular swimming spots for visitors and locals in Coral Gables. Just be ready: the water is a little chilly!
Note: This pool is closed during winter and usually opens back up to the public in mid-February.