Phra Nang Beach is accessible only by long-tail boat about a 20-minute ride from Ao Nang (in Krabi Province). The velvety sand is best from May to December during low-season when you can rent a sea kayak to explore the sandstone karsts and limestone caves just offshore go snorkeling among the shallow waters coral reefs or try your hand rock climbing without competing for space.
" The Great Blue Hole, Belize " It was formed as a limestone cave system during the last glacial period when sea levels were much lower. As the ocean began to rise again, the caves flooded, and the roof collapsed.Believed to be the world’s largest feature of its kind, the Great Blue Hole is part of the larger Belize Barrier Reef Reserve System
The Jeita Grotto is a system of two separate, but interconnected, karstic limestone caves spanning an overall length of nearly 9 kilometres (5.6 mi). The caves are situated in the Nahr al-Kalb valley within the locality of Jeita, 18 kilometres (11 mi) north of the Lebanese capital Beirut. - Wikipedia
By venturing into the 30-million-year-old limestone caves on New Zealand’s North Island, photographer Joseph Michael was able to capture magical images of the glowworms that call this place home. Against the natural backdrop that the cave provides, it looks as though there are hundreds of miniature, blue-tinted stars, but this is actually the work of glowworms known as Arachnocampa luminosa.