Previous Image Extraordinary-World-Phenomenons-6 The Great Blue Hole in Belize – A large submarine sinkhole which is over 984 feet across and 407 feet deep. The sinkhole was formed during several episodes of quaternary glaciation when sea levels were much lower. (Kurt Amsler/Ardea/Caters News) Share this:Click to share on Facebook (Opens in new window)Click to share on Twitter (Opens in new window)Click to email a link to a friend (Opens in new window)Click to print (Opens in new window)Like this:Like Loading...