Something is submerged up ahead. As your boat approaches the rocky island, the color of the water begins to change from azure to turquoise to completely clear. That’s expected when you drift toward shallow bays. But there are large spots a few feet beneath the cyan waves. The closer you inch, the larger and darker they become. And they aren’t moving at all.

Those dark spots are actually stones. Not stony corals that have built up over time to become colonies. They’re real stones that were moved around the island to create houses, public buildings, and a shipyard. As your eyes move toward the shore, you find a stone staircase ascending from the water. It leads to the ruins of more houses, a church, and tombs with arched roofs. You found a partially sunken city.

It’s an ancient city called Dolchiste. The Lycians built city-states along present-day Turkey’s southern coast in the 2nd millennium BC. One of them was called Simena. It included a long, two-square-mile island just offshore. Dolchiste was built on its northern coast facing the mainland. The city was destroyed by a violent earthquake. It probably sunk during the aftershocks. The Byzantines attempted to rebuild it. It’s their church that’s still standing today. Arabs kept attacking the island, though. It was eventually abandoned.

The island is now called Kekova. Long after the Byzantines departed, the uninhabited—except for a bunch of wild goats—island was part of a dispute between Italy and Turkey. Kekova went to Turkey in 1932. It’s been part of the popular Antalya coast ever since. Then in 1990, it became a protected area for its natural and cultural beauty. In addition to the ruins, a series of lagoons, hidden beaches, and wild thyme make Kekova an enchanting day trip. Now UNESCO has placed it on its tentative list of World Heritage Sites. A lot more boats will surely be following yours. But at least for today, you have this mysterious island all to yourself. Savor it.