The Azure Window (), also known as the Dwejra Window (), was a natural arch on the island of Gozo, located just off the shores of Malta. The limestone feature, which was in Dwejra Bay close to the Inland Sea and Fungus Rock, was one of the island's major tourist attractions until it collapsed in stormy weather on 8 March 2017. The arch, together with other natural features in the area, has appeared in a number of international films and media productions. The rock formation, which consisted of a pillar rising from the sea joined to the cliff by a horizontal slab, was created by the collapse of a sea cave, probably during the 19th century. The final collapse followed a century of natural erosion, during which large sections of the limestone arch had broken off and fallen into the sea. History Formation The Azure Window developed through sea erosion of a cliff face. The progress starts with an initial notch resulting from wave action. This space devoid of rock then causes tensile stresses that lead to the formation of a vertical joint extending upwards from the notch. This joint would progressively become wider, first forming a cave and eventually an arch. The end of the lifecycle of the arch is reached when erosion finally progressed so far that the roof of the arch gets heavier than the pillars can support. It is not known exactly when the arch came to being, but the entire process is believed to have taken around 500 years. The arch is not mentioned in 17th- and 18th-century descriptions of the Dwejra area, which was already famous due to the nearby Fungus Rock, so it probably did not exist then. Giovanni Francesco Abela's 1647 book Della Descrizione di Malta and De Soldanis' 1746 manuscript Il Gozo Antico-Moderno e Sacro-Profano both mention a Tieqa Żerqa (written archaically as Tieka Szerka) or Għar iż-Żerqa, but this referred to the cave entrance to the nearby Inland Sea. Therefore, it is likely that when the Azure Window formed it inherited its name from this other cave. The earliest known record of the Azure Window is in an 1824 illustration of the nearby Dwejra Tower. However, it is shown in the background of the image, and it is unclear whether it was still a cave or if it had already developed into an arch. A pencil drawing by Lt Col.