Banganga Tank is an ancient water tank which is part of the Walkeshwar Temple Complex in Malabar Hill area of Mumbai. The Tank was built in the 1127 AD, by Lakshman Prabhu, a minister in the court of Silhara dynasty kings of Thane.
According to local legend, it sprang forth when the Lord Ram, the exiled hero of the epic Ramayana, stopped at the spot in search of his kidnapped wife Sita. As the legend goes, overcome with fatigue and thirst, Rama asked his brother Lakshman to bring him some water. Laxman instantly shot an arrow into the ground, and water gushed forth from the ground, creating a tributary of the Ganges, which flows over a thousand miles away, hence its name, Banganga, the Ganga created on a baan (arrow).