Kerak Castle (Arabic: قلعة الكرك, romanized: Qal'at al-Karak) is a large Crusader castle located in al-Karak, Jordan. It is one of the largest crusader castles in the Levant. Construction of the castle began in the 1140s, under Pagan and Fulk, King of Jerusalem. The Crusaders called it Crac des Moabites or "Karak in Moab", as it is referred to in history books. It was also colloquially referred to as Krak of the Desert.
About the source: Wikipedia
Wikipedia is a multilingual online encyclopedia created and maintained as an open collaboration project by a community of volunteer editors, using a wiki-based editing system. It is the largest and most popular general reference work on the World Wide Web, and is one of the 20 most popular websites ranked by Alexa, as of March 2020. It features exclusively free content and no commercial ads, and is owned and supported by the Wikimedia Foundation, a non-profit organization funded primarily through donations.