Until 1987 these islands were closed to land-based tourism and could only be viewed from aboard a vessel. With their clear, aquamarine waters and ecologically diverse tropical, mountainous landscapes, these islands were the location for the filming of the romantic adventure film The Blue Lagoon (both the 1949 and 1980 versions). The islands are famous for the limestone Sawa-i-lau caves, which must be accessed by swimming at low tide through an underwater tunnel. Nabukeru villagers assert that the cave is the heart of the Yasawas.