Teide, or Mount Teide, (Spanish: El Teide, Pico del Teide, pronounced [ˈpiko ðel ˈtejðe], "Peak of Teide") is a volcano on Tenerife in the Canary Islands, Spain. Its summit (at 3,715 m (12,188 ft)) is the highest point in Spain and the highest point above sea level in the islands of the Atlantic. If measured from the ocean floor, its height of 7,500 m (24,600 ft) makes Teide the third-highest volcano in the world, and is described by UNESCO and NASA as Earth's third-tallest volcanic structure. Teide's elevation above sea level makes Tenerife the tenth highest island in the world.
Teide started forming 170,000 years ago due to volcanic activity following a catastrophic landslide. Teide's base is situated in Las Cañadas crater (the remains of an older, eroded, extinct volcano) at a height of around 2,190 m (7,190 ft) above sea level. Teide is an active volcano: its most recent eruption occurred in late 1909 from the El Chinyero vent on the northwestern Santiago rift. The United Nations Committee for Disaster Mitigation designated Teide a Decade Volcano because of its history of destructive eruptions and its proximity to several large towns, of which the closest are Garachico, Icod de los Vinos and Puerto de la Cruz. Teide, Pico Viejo and Montaña Blanca form the Central Volcanic Complex of Tenerife.
The volcano and its surroundings make up Teide National Park, which has an area of 18,900 hectares (47,000 acres) and was named a World Heritage Site by UNESCO in 2007. Teide is the most visited natural wonder of Spain, the most visited national park in Spain and Europe and – by 2015 – the eighth most visited in the world, with some 3 million visitors yearly. In 2016, it was visited by 4,079,823 visitors and tourists, reaching a historical record. Teide Observatory, a major international astronomical observatory, is located on the slopes of the mountain.