It's called the Great Blue Hole. Scuba divers and snorkelers have been cruising the surface waters for decades, but few have dared to venture deeper and explore what lies beyond the blackness.

Belize’s Great Blue Hole, pictured here, is probably the most recognizable blue hole. The newly discovered blue hole off the ...

Declared a UNESCO World Heritage Site in 1996 – along with six other areas surrounding Belize's barrier reef – the Great Blue Hole remains one of the world's most distinguished scuba sites.

This finding suggests that the Great Blue Hole was once a dry cave that formed around 14,000 years ago. It was later flooded and collapsed after the Ice Age ended when sea levels on Earth rose ...