Adalaj is a village to the north of Ahmedabad. The Vav' (step-well) at Adalaj derives its name from the lady patron, Ruda, wife of the Vaghela chief, Virsinh. There is an inscription in Sanskrit, which gives the entire history with exact dates.
Step-well, perhaps, is a unique feature of Gujarat, which speaks of the history, culture, and architecture. It was also considered to be a religious obligation.
Many kings, rulers and the rich people of Gujarat spent huge money for constructing these step-wells. These used to be frequented by travellers and caravans as stopovers on their trade routes.