The Azure Window (Maltese: Tieqa Żerqa) is a Limestone natural arch on the Maltese island of Gozo. It is situated near Dwejra Bay on the Inland Sea. The formation, which was created after two limestone sea caves collapsed, is popular with scuba divers.
The Azure Window is made of a Maltese limestone known as Globigerina. This is the second oldest rock found on the islands covering almost 70% of its area. The rock, which is subject to erosion, gives Malta its distinctive coast and interior. Thickness of the limestone ranges from 23 m (75 ft) near Fort Chambrayon Gozo up to 207 m (679 ft) around Marsaxlokk on Malta. The 28 m (92 ft) high arch consists of yellow to pale-grey limestones comprising the remains of the marine organism globigerinid foraminifera.
The arch is disintegrating because large pieces of rock have begun to fall from the underside of the arch. The rate suggests that the arch will completely disintegrate within a few years. Its dangerous condition has led to warning notices being placed along the cliffs to stop people walking over the top of the arch. In April 2012 a large piece of rock was dislocated and resulted in the window being made larger and more unstable, as well as a reduction in its nearly perfect oblong shape.