The Sacred City of Anuradhapura was begun c500 BCE. King Pandukhapura laid out gardens along the Malwatte Oya River and also a large garden of fruit and flowers - the Mahamegha Gardens (Great Raincloud Gardens, from maha - great; megha - rain cloud), in which the sacred Bo Tree still survives. It was a cutting from the tree under which the Lord Buddha reached the state of nirvana. The gardens around the Tisa Wewa tank survive and have large boulders which were used for summer houses. The Kuttam Poxuna were monk's bathing ponds.