The historic heritage of Ceuta includes magnificent monumental sites, such as the Murallas Reales (Royal Walls) and other examples of fortifications from the Middle Ages to the present day. In addition, Ceuta has numerous museums and archaeological sites that can be visited, as well as Baroque temples and beautiful examples of 20th century architecture. The Murallas Reales building is an example of 18th century poliorcetic or siege architecture and has a magnificent Baroque doorway. The inside is dedicated to large temporary exhibitions. Batería de Valdeaguas is a coastal battery built at the end of the 19th century, designed by Luis Sánchez de la Campa, for three large-calibre artillery guns. The guns were removed in 1941. Catedral de Ntra. Sra. de la Asunción was built on the site of the old mosque-cathedral at the end of the 17th century according to plans by the master-architect Juan de Ochoa, and was consecrated in the 18th century. Museo Militar "El Desnarigado" was opened in 1984, it takes its name from a Berber pirate nicknamed "el desnarigado" (the flat-nosed one), an escapee from an Algerian prison-mine, who settled in the cove of the same name in 1417. Fortines y torres neomedievales: The natural border of Ceuta and Morocco is delimited by seven hills, crowned by seven medieval style towers built in the 19th century for the surveillance and defence of the city: Torre de Pinies, Aranguren, Anyera, Mendizábal, Isabel II, San Francisco and the Príncipe Alfonso fort.