Explanation:

 Ana Sagar Lake is an artificial lake situated in the city of Ajmer in Rajasthan state in India. It was built by Arnoraja (alias Ana), the grandfather of Prithviraj Chauhan, in 1135 -1150 AD and is named after him. The catchments were built with the help of local populace. The lake is spread over 13 Kilometers. The Baradari or pavilions were built by Shahjahan in 1637 and Daulat Bagh Gardens by Jehangir.