Phosphorous Cave

Phosphorus Cave sits on the southwestern shore of Cennet Island (also called Paradise Island), just off the coast near Marmaris, and is reached only by boat through a narrow entrance in the rock. Despite the name, there is no phosphorus involved — the glow comes from sunlight refracting through the clear turquoise water onto the pale rock of the cave walls and ceiling, an effect early visitors likened to phosphorescence.

The cave is also known as the Dilek Cave, or "Wish Cave," after a tradition among visitors of tossing a coin into the water and making a wish. Inside, the contrast between the white rock and the shifting shades of turquoise makes it a popular photo stop on boat tours, and many visitors take the chance to swim or snorkel in the sheltered water, though some of the surrounding rock is sharp enough to warrant caution.

A visit typically lasts only 10 to 15 minutes as one stop within a longer boat tour, and it is a classic stop on a Marmaris blue cruise itinerary that usually also takes in İçmeler beach and the wider Marmaris National Park nearby.