Kayangan Lake is the postcard image of Coron: a brackish pool of luminous green-blue water enclosed by jagged karst limestone, reached by a short steep climb over a saddle from the boat landing. The viewpoint near the top is one of the most photographed spots in the Philippines.
The water is exceptionally clear and warm; you can swim with a snorkel and see straight down to submerged rock walls and small fish. The lake is sacred to the indigenous Tagbanua people, who manage Coron Island and require visitors to follow their rules — daylight access only, no sunscreen, no food on the platforms. Boatmen tend to push tours to arrive early; aim for the first or last slot to escape the crowds.