Jaisalmer Fort, also known as Sonar Qila (Golden Fort), was built in the 12th century by Rawal Jaisal, the ruler of the city at that time. The fort is made of sandstone and stands high on a hill. It is one of the few living forts in the world, meaning that people still live within its walls. The fort witnessed numerous battles and invasions and remained undefeated due to its strong fortifications. Today it is a popular tourist attraction and is a UNESCO World Heritage Site.