The Canary Islands (/kəˈnɛəri/; Spanish: Islas Canarias, pronounced [ˈizlas kaˈnaɾjas]) are a Spanish archipelago and the southernmost autonomous community of Spain located in the Atlantic Ocean, 100 kilometres (62 miles) west of Morocco at the closest point. The Canary Islands, which are also known informally as the Canaries, are among the outermost regions (OMR) of the European Union proper. It is also one of eight regions with special consideration of historical nationality as recognized by the Spanish Government. The Canary Islands belong to the African Plate like the Spanish cities of Ceuta and Melilla, the two on the African mainland. The eight main islands are (from largest to smallest in area) Tenerife, Fuerteventura, Gran Canaria, Lanzarote, La Palma, La Gomera, El Hierro and La Graciosa. The archipelago includes many smaller islands and islets: Alegranza, Isla de Lobos, Montaña Clara, Roque del Oeste and Roque del Este. It also includes a series of adjacent roques (those of Salmor, Fasnia, Bonanza, Garachico and Anaga). In ancient times, the island chain was often referred to as "the Fortunate Isles". The Canary Islands are the most southerly region of Spain and the largest and most populated archipelago of the Macaronesia region. Historically, the Canary Islands have been considered a bridge between four continents: Africa, North America, South America and Europe. The Canary Islands currently have a population of 2,127,685 inhabitants and a density of 283.08 inhabitants/km², being the eighth most populous autonomous community. The population of the archipelago is mostly concentrated in the two capital islands, around 43% on the island of Tenerife and 40% on the island of Gran Canaria. The archipelago's beaches, climate and important natural attractions, especially Maspalomas in Gran Canaria and Teide National Park and Mount Teide (a World Heritage Site) in Tenerife (the third tallest volcano in the world measured from its base on the ocean floor), make it a major tourist destination with over 12 million visitors per year, especially Tenerife, Gran Canaria, Fuerteventura and Lanzarote. The islands have a subtropical climate, with long hot summers and moderately warm winters. The precipitation levels and the level of maritime moderation vary depending on location and elevation. Green areas as well as desert exist on the archipelago. Due to their location above the temperature inversion layer, the high mountains of these islands are ideal for astronomical observation. For this reason, two professional observatories, Teide Observatory on the island of Tenerife and Roque de los Muchachos Observatory on the island of La Palma, have been built on the islands. In 1927, the Province of Canary Islands was split into two provinces. The autonomous community of the Canary Islands was established in 1982. Its capital is shared by the cities of Santa Cruz de Tenerife and Las Palmas de Gran Canaria, which in turn are the capitals of the provinces of Santa Cruz de Tenerife and Las Palmas. Las Palmas de Gran Canaria has been the largest city in the Canaries since 1768, except for a brief period in the 1910s. Between the 1833 territorial division of Spain and 1927 Santa Cruz de Tenerife was the sole capital of the Canary Islands. In 1927 a decree ordered that the capital of the Canary Islands be shared, as it remains at present. The third largest city of the Canary Islands is San Cristóbal de La Laguna (a World Heritage Site) on Tenerife. This city is also home to the Consejo Consultivo de Canarias, which is the supreme consultative body of the Canary Islands. During the time of the Spanish Empire, the Canaries were the main stopover for Spanish galleons on their way to the Americas, which came south to catch the prevailing north-easterly trade winds.