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).