Palau
A UNESCO World Heritage marine and island area comprising around 445 limestone islets in Palau's Southern Lagoon between Koror and Peleliu, widely regarded as Palau's premier diving region.
The Rock Islands Southern Lagoon was inscribed as a mixed UNESCO World Heritage Site in 2012, covering roughly 100,200 hectares of coral reefs, lagoon, and coralline limestone islands. It contains the highest concentration of marine lakes in the world, including the snorkel-only Jellyfish Lake, and supports very high marine biodiversity with hundreds of fish and coral species, sharks, and manta rays. Diving is described as the largest industry in Palau, concentrated here at well-known sites such as Blue Corner, Blue Holes, and German Channel.