The Great Blue Hole
On-shore caves of similar formation, as large collapsed sinkholes, are well known in Belize and in the Yucatan Peninsula where they are known as centos. Unlike the mainland cenotes which often link to underwater cave systems, there is little evidence of horizontal development in the Blue Hole.
In 2012 Discovery Channel ranked the Great Blue Hole as number one on its list of "The 10 Most Amazing Places on Earth".
Even though the Great Blue Hole is considered a "bucket list dive" one should be aware that it is not for divers of all skill levels – a prerequisite is logging more than 24 dives. It is also not a 'colourful dive', instead, divers witness a dark cave with impressive stalactites.