The Azure Window and the Blue Hole

Two geological wonders sit side-by-side on the Maltese island of Gozo: the Azure Window and the Blue Hole. 

The window is a towering rock formation reaching 328 feet (100 meters) high with a precarious table structure that makes it popular for cliff divers. Below it is another wonder with a collapsed underwater limestone cave known as the Blue Hole. The site reaches a maximum depth of some 200 feet (60+ meters). It's accessed by divers through a 262-foot tunnel, and underwater you can find a beautiful array of marine life including octopi, fireworms, morays, and sea horses.

The Azure Window is a national landmark and known as the setting for dramatic scenes in film and TV, most recently in Game of Thrones. It was one of the most popular sunset spots on Gozo Island in Dwejra region (the west coast of the island)

Unfortunately, the Azure Window is wearing down. In April of 2012, it got a little wider when part of it broke off.  When that happens, there is a plan to rechristen it the 'Azure Pinnacle.'

Update March 2017: The Azure Window and the Stack (Pinnacle) collapsed on March 8, 2017, after heavy storms. Officials are testing whether the Blue Hole has been affected by the collapse.