Stepwell construction is known to have gone on from at least AD 600 in the south western region of Gujarat, India. The practical idea even spread north to the state of Rajasthan, along the western border of India where several thousands of these wells were built. The construction of these stepwells hit its peak from the 11th to 16th century.[2] Most existing stepwells date from the last 800 years. There are suggestions that they may have originated much earlier, and precursors to them can be seen in the Indus Valley civilisation.