There are several stepped wells or baolis built with rubble
stone in and around Mehrauli, two among which are better known than
others. 'Gandhak-ki-Baoli', so called because of the smell of sulphur
(gandhak) in its waters, lies about 100m south of Adham Khan's tomb.
Believed to have been built in the reign of Iltutmish (1211-1236), it has five tiers, with a circular well at its southern end. It is also known as the diving well, since divers jump into it from the upper tiers for the amusement of visitors.
Further 400m south is another four-tiered stepped well, known as 'Rajon-ki-Bain', which seems to have derived its name from being used by 'Masons' (Raj). Steps within its top walls connect it with a mosque, wherein a chhatri bears an inscription of 912 A.H. (1506), stating that it was built during the reign of Sikandar Lodi (1489-1517).