{{Infobox protected area | name = La Portada Natural Monument | iucn_category = III | image = MonumentoNaturalLaPortada(4).jpg | image_caption = La Portada Natural Monument | location = [[Antofagasta Region]], [[Chile]] | nearest_city = | coordinates = {{coord|23|30|23|S|70|25|37|W|format=dms|display=inline,title}} | area = 0.3127 km<sup>2</sup> | established = | visitation_num = | visitation_year = | governing_body = [[Corporación Nacional Forestal]] }} '''La Portada''' ([[Spanish language|Spanish]]: "The Gateway") is a [[natural arch]] on the coast of [[Chile]], {{convert|18|km|mi|abbr=on}} north of [[Antofagasta]].<ref name="readersnatural">{{Cite book|title=Natural Wonders of the World|publisher=Reader's Digest Association, Inc|year=1980|isbn=0-89577-087-3|editor-last=Scheffel|editor-first=Richard L.|location=United States of America|pages=301|editor-last2=Wernet|editor-first2=Susan J.}}</ref> 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 == {{see also|Coastal Cliff of northern Chile|La Portada Formation|La Negra Formation}} The La Portada Natural Monument covers an area of 31.27 [[hectare]]s (77.27 [[acre]]s), and its geomorphological features and remaining fossils stand out in the form of an arch.

The arch of La Portada is 43&nbsp;m (140&nbsp;ft) high, 23&nbsp;m (75&nbsp;ft) wide, and 70&nbsp;m (230&nbsp;ft) long. It has a base of black [[andesite]] stone, around which are arranged marine [[sedimentary rock]]s, a stratum of yellowing [[sandstone]], and layers of the remaining fossils of shells dating back 35 to 2 million years ago.<ref name="readersnatural" /> 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''.

Between 2003 and 2008, the monument was closed due to a landslide of an important part of its cliffs, which required remodeling of the access route and its surroundings.

Since 2010, access to the beach is prohibited to protect the flora and fauna.

[[Image:MonumentoNaturalLaPortada.jpg|thumb|center|550px|Panorama of La Portada Natural Monument]]

== Fauna == The natural monument constitutes an observation site for [[guano]] birds such as [[Peruvian booby]] (''Sula variegata'') and [[Inca tern]]s (''Larosterna inca''), as well as [[Guanay cormorant]]s (''Phalacrocorax bougainvillii''), [[kelp gull]]s (''Larus dominicanus''), [[grey gull]]s (''Larus modestus''), [[Belcher's gull]]s (''Larus belcheri''), and [[pelican]]s.

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 {{convert|18|km|mi|abbr=on}} 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 == {{Reflist}}

== External links == {{commons|Monumento Natural La Portada|La Portada Natural Monument}} * {{in lang|es}} [http://www.conaf.cl/ Corporación Nacional Forestal]. * {{in lang|es}} [http://www.sernatur.cl/ Servicio Nacional de Turismo]. * [http://portada.biz/ La Portada].

{{Natural Monuments of Chile}}

[[Category:Landforms of Antofagasta Region]] [[Category:Natural monuments of Chile]] [[Category:Rock formations of Chile]] [[Category:Natural arches]] [[Category:Protected areas of Antofagasta Region]] [[Category:Coasts of Antofagasta Region]]