Alanya Castle (Alanya Kalesi) is a medieval castle in the southern Turkish city of Alanya.
Most of the castle was built in the 13th century under the Seljuq Sultanate of Rûm following the city's conquest in 1220 by Alaeddin Keykubad I as part of a building campaign that included the Kızıl Kule.
The castle was built on the remnants of earlier Byzantine era and Roman era fortifications. After the area was pacified under the Ottoman Empire, the castle ceased to be purely defensive, and numerous villas were built inside the walls during the 19th century. Today the building is an open-air museum. Access to the seaward castle is ticketed, but much of the area inside the wall, including the landward castle is open to the general public.
The castle is located 250 metres (820 ft) high on a rocky peninsula jutting into the Mediterranean Sea, which protects it from three sides. The wall which surrounds the castle is 6.5 kilometres (4.0 mi) long and includes 140 towers. 400 different cisterns were built to serve the castle. In 2009, city officials filed to include Alanya Castle and Tersane as UNESCO World Heritage Sites, and were named to the 2009 Tentative List.
Alanya (Turkish pronunciation: [aˈɫanja]), formerly Alaiye, is a beach resort city and a component district of Antalya Province on the southern coast of Turkey, in the country's Mediterranean Region, 138 kilometres (86 mi) east of the city of Antalya. As of Turkey's 2010 Census, the city had a population of 98,627, while the district that includes the city and its built-up region had an area of 1,598.51 km2 and 248,286 inhabitants.
Because of its natural strategic position on a small peninsula into the Mediterranean Sea below the Taurus Mountains, Alanya has been a local stronghold for many Mediterranean-based empires, including the Ptolemaic, Seleucid, Roman, Byzantine, and Ottoman Empires. Alanya's greatest political importance came in the Middle Ages, with the Seljuk Sultanate of Rûm under the rule of Alaeddin Kayqubad I, from whom the city derives its name. His building campaign resulted in many of the city's landmarks, such as the Kızıl Kule (Red Tower), Tersane (Shipyard), and Alanya Castle.