It is located at the centre of Rajasthan. It is also known as heart of Rajasthan. The city was established as "Ajayameru" (translated as "Invincible Hills") by a Chahamana ruler, either Ajayaraja I or Ajayaraja II, and served as their capital until the 12th century CE. Ajmer is surrounded by the Aravalli Mountains. Today, Ajmer is a popular pilgrimage centre for the Hindus as well as Muslims. Especially famous is the Dargah Sharif-tomb of the Sufi saint Khwaja Moinuddin Chisti, which is equally revered by the Hindus and Muslims. The Urs festival is an annual festival held at Ajmer, Rajasthan, India which commemorates the anniversary of the death of Sufi saint Moinuddin Chishti (founder of the Chishtiya Sufi order in India).