"In the first century AD, the slippery shores of the major rivers were tamed by the construction of ghats, long, shallow sets of stairs and landings. The same approach was applied to the construction of a new kind of well…Among the largest, if not the largest, and perhaps the most visually spectacular stepwells, Chand Baori is a deep four sided structure with an immense temple on one face. 3500 Escher-esqe terraced steps march down the other three sides 13 stories to a depth of 100 feet. The construction dates to the tenth century, and is dedicated to Harshat Mata, goddess of joy and happiness."
from Atlas Obscura (thanks Alex)