Erected in the 1850s to prevent merchant ships from disappearing in the Bermuda Triangle, the 152-foot tall Great Isaac Lighthouse has become more of a participant in the area's mysteries than a protector.
The cay itself is one giant coral head - a colony of genetically identical coral polyps - rising a few feet out of the area’s shallow, dangerous reefs. Razor sharp terrain makes the land inhospitable, and difficult to traverse.
Until 1969, the barren island was occupied by lighthouse keepers. On August 4, 1969 it was discovered that they had gone missing. Their bodies never found and it is believed they may have been killed in a hurricane the passed through on August 1st through the 2nd. After their disappearance, the Great Isaac Light was automated, shining a white beam every 15 seconds to sailors up to 23 nautical miles away. The rest of the compound’s buildings have been left to crumble.
Though the cay’s grounds are open to the public, the bottom few stairs in the tower are missing and the storage bunkers and buildings are locked. Exploring is expected and part of the fun, though falling on the rocks or cutting yourself while shimmying up the lighthouse’s rusty staircase are both real possibilities, and may earn you a fresh tetanus shot. Moderate agility and seafaring skill is required to make landfall.
Nineteenth century lore has it that a ship wrecked on Great Isaac Cay water, killing everyone aboard except one young infant. Locals claim that the infant's mother (known as the Grey Lady) can still be seen roaming the island, and her wails of sorrow can be heard on full moons.