Jaipur is the capital and largest city of the Indian state of Rajasthan. It was founded on 18 November 1727 by Maharaja Sawai Jai Singh II, the ruler of Amber, after whom the city has been named. The city today has a population of 3.1 million. Jaipur is known as the Pink City of India. The city is remarkable among pre-modern Indian cities for the width and regularity of its streets which are laid out into six sectors separated by broad streets 34m (111ft) wide. The urban quarters are further divided by networks of gridded streets. Five quarters wrap around the east, south, and west sides of a central palace quarter, with a sixth quarter immediately to the east. The Palace quarter encloses the sprawling Hawa Mahal palace complex, formal gardens, and a small lake. Nahargarh Fort, which was the residence of the King Sawai Jai Singh II, crowns the hill in the northwest corner of the old city. The observatory, Jantar Mantar, is one of the World Heritage Sites.