Stepwells are a distinctive form of subterranean water resource and storage systems on the Indian subcontinent, and have been constructed since the third millennium BC. Rani ki vav was built in the complex Maru-Gurjara architectural style with an inverted temple and seven levels of stairs and holds more than 500 principal sculptures.
Rani ki vav (Queen’s step well) was constructed during the rule of the Chaulukya dynasty. It is generally assumed that it was built in the memory of Bhima I (r. c. 1022–1064) by his widowed queen Udayamati and probably completed by Udayamati and Karna after his death. A reference to Udayamati building the monument is in Prabandha Chintamani, composed by the Jain monk Merunga Suri in 1304 AD.
The stepwell was later flooded by the nearby Saraswati River and silted over until the late 1980s. When it was excavated by the Archaeological Survey of India, the carvings were found in pristine condition.
This magnificent east-facing step well measures approximately 64 m long, 20 m wide & 27 m deep. A stepped corridor compartmented at regular intervals pillared multistory pavilions is a unique feature. It was one of the largest and the most sumptuous structures of its type. It became silted up and much of it is not visible now, except for some rows of sculptured panels in the circular part of the well. Among its ruins one pillar still stands which is an excellent example of this period of design. A part only of the west well is extant from which it appears that the wall had been built of brick and faced with stone. From this wall project vertical brackets in pairs, which supported the different galleries of the well shaft proper. The bracketing is arranged in tiers and is richly carved. The minute and exquisite carving of this vav is one of the finest specimens of its kind. Befitting its name, the Rani-Ki-Vav is now considered to be the queen among step wells of India.
There is also a small gate below the last step of the step well, with a 30 kilometre tunnel, currently blocked by stones and mud) which leads to the town of Sidhpur near Patan. It was used as an escape gateway for the king, who built the step well in the times of defeat.