" 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 Waitomo Caves are located just outside the Waitomo Township (New Zealand). It is a famous attraction because of the glowworms, native bioluminescent creatures that live in the caves and produce a blue-green light that decorates the ceiling with a twinkling glow which reminds of faraway galaxies.
Blue Hole in Santa Rosa, NM | Blue Hole appears in the midst of the desert like a great blue gem. ( Agua Negra Chiquita) Once known as Blue Lake, it is one of seven sister lakes connected underground by a vast system of water.