Image:MonumentoNaturalLaPortada(4).jpg '''La Portada''' (Spanish: "The Gateway") is a Natural_arch on the coast of Chile, 18 km (11 miles) north of Antofagasta. It is one of fifteen natural monuments included among the Protected_areas_of_Chile. There is another similar but smaller structure in the Spa_town of Pucatrihue, Osorno_Province. == Description == The La Portada Natural Monument covers an area of 31.27 Hectares (77.27 Acres), and its geomorphological features and remaining fossils stand out in the form of an arch. The arch of La Portada is 43 m (140 feet) high, 23 m (75 feet) wide, and 70 m (230 feet) long. It has a base of black Andesite stone, around which are arranged marine Sedimentary_rocks, a strata of yellowing Sandstone, and layers of the remaining fossils of shells dating back 35 to 2 million years ago. All this was formed during a long process of marine erosion. The arch is surrounded by coastal cliffs that were also formed by marine erosion. They reach a maximum height of 52 m above sea level. On 5_October 1990, it was declared a natural monument under Supreme Decree #51 of the Ministry of Agriculture, published in the Diario Oficial. Since March_2003, this natural monument remains closed due to a landslide of an important part of its cliffs, which blocked access to its beach. For this reason, a remodeling of the access route and its surroundings is planned. Image:MonumentoNaturalLaPortada.jpg == Fauna == The natural monument constitutes an observation site for Guano birds such as ''Piqueros'' (''Sula_variegata'') and Inca Terns (''Larosterna_inca''), as well as Guanay Cormorants (''Phalacrocorax_bougainvillii''), Kelp Gulls (''Larus_dominicanus'') ''Garuma'' Gulls (''Larus modestus''), Peruan Gulls (''Larus Belcheri''), and pelicans (''Pelecanus''). Occasionally one can also observe mammals such as the South American Fur Seal (''Arctocephalus_australis'') or the common dolphin (''Delphinus_delphis''). == Access == La Portada is located 18 km (11 miles) north of Antofagasta, which can be accessed by Route 1 Antofagasta-Tocopilla, from which an access road diverges at kilometer 20. The monument is found near the Cerro_Moreno_International_Airport and La_Chimba_National_Reserve. == References == * This article was originally translated from the Spanish Wikipedia article, ''Monumento Natural La Portada''. == External links == {{commons|Monumento Natural La Portada|La Portada Natural Monument}} * {{es icon}} Corporación Nacional Forestal. * {{es icon}} Servicio Nacional de Turismo. Category:Geography_of_Chile Category:Natural_arches Es:Monumento_Natural_La_Portada