Built by Sultan Ala-ud-din Khilji in the 13th century, Hauz Khas means ‘noble tank', and its reservoir once covered 28 hectares. It collected enough water during the monsoon to last Siri Fort throughout the dry season. Today it's much smaller, but still a beautiful place to be, thronged by birds and surrounded by parkland. Alongside it are the ruins of Feroz Shah’s 14th-century madrasa (religious school) and tomb, which he had built before his death in 1388.
To reach the lake shore, cut through the adjacent Deer Park (daylight hours), which has more ruined tombs and a well-stocked deer enclosure. There are numerous Lodi-era tombs scattered along the access road to Hauz Khas Village, and in nearby Green Park.