Neptune Memorial Reef, Artificial reef and underwater cemetery off the coast of Florida, US

Neptune Memorial Reef is an artificial reef and underwater cemetery located off the coast of Key Biscayne, Miami, Florida, roughly 3 miles (5 km) from shore. It features sculptures, statues, and architectural elements placed on the seafloor that together form a layout resembling a submerged city.

The project was originally conceived as the Atlantis Reef Project, designed by Gary Levine and artist Kim Brandell in the early 2000s. Construction began around 2007 and had to be adapted after a powerful hurricane hit the area, leading engineers to strengthen the structures against future storms.

Divers who visit the reef find statues, benches, and pathways along the seafloor that resemble a sunken city. Many of the structures are now covered with coral and sea creatures, giving the site a living quality that changes with each visit.

The site lies 3.25 miles (5.2 km) off Key Biscayne in about 40 feet (12 m) of water, reachable only by boat; several operators run snorkel and scuba trips. It sits in a special management zone where boaters and divers are welcome but fishing and lobster-taking are prohibited. The structures were engineered to withstand the strongest storm of the past 100 years.

The first phase of the reef was designed to hold at least 850 sets of cremated remains, but long-term plans allow space for over 125,000 burials. The cremated remains are mixed directly into the cement used to form the structures, meaning each sculpture is literally built from the people it honors.