The largest freshwater swimming pool in the U.S., the Venetian Pool in Coral Gables is a one-of-a-kind water feature that is emptied and refilled every day during the summer just to keep the waters fresh and clean.

Built in 1923 out of the remains of an abandoned coral rock quarry, the public pool was modeled after a Venetian grotto with the intention of bringing a piece of Mediterranean style to the States. A scenic bridge was built overlooking the pool, along with mooring posts for gondolas that were to be able to pull right up to the pool, although this feature was later scrapped. The pool also connects to a number of natural grotto caves that swimmers can explore.

The water in the Venetian Pool is always a clean and clear shade of blue, thanks to the unique natural filtering system. During its early years, the pool was drained each day and the water freshly replenished from artesian springs on the site. This process, however, came under fire when water conservationists warned that it was draining local aquifers. In response, a new system was devised to drain the pool water back into the aquifer, allowing natural filtration to clean up the wastewater. During Florida’s hot spring and summer, this refilling system is still in place, creating a pool of perfectly crisp water to swim in each day.

The constant draining of the pool has also allowed it to be used for events such as symphony concerts, which take advantage of the empty quarry’s natural acoustics. The Venetian Pool is the only swimming pool to be protected by the National Register of Historic Places, making it a site that should run swimmingly for years to come.

Update as of January 2023: The pools are currently closed indefinitely.