From ancient myths of sea monsters lurking below to Jules Verne’s Twenty Thousand Leagues Under the Sea, the ocean has long been both a source of fear and fascination. For Captain George Bond, a Navy medical officer in the 1960s, the deep sea was humanity’s next frontier. Undersea agriculture, deep sea mining, and human colonies on the ocean floor made up his dream for the future.

Today we bring you the story of the U.S. Navy’s little-known experiment building homes on the ocean floor. They called it, Sealab.