Rani-ki-Vav (the Queen’s Stepwell) at Patan, Gujarat Rani-ki-Vav, on the banks of the Saraswati River, was initially built as a memorial to a king in the 11th century AD. Stepwells are a distinctive form of subterranean water resource and storage systems on the Indian subcontinent, and have been constructed since the 3rd millennium BC. They evolved over time from what was basically a pit in sandy