Baolies are water harvesting structures mostly constructed during the period of Lodhi and Mughals. They can be seen in various parts of North India. The city of New Delhi has many of them.
As the word suggests they are stepped wells. They include a catchment area (supposed to be a forest area, now explored and exploited by men), a deep open/closed well and a stepped region which can be used as a pond. For more details and photos contact aji_aug@Yahoo.co.in