Near the road approaching Yogapitha from the ISKCON temple, there is a culvert just after the Mayapur Polyclinic. When you cross the culvert, take the dirt road on the left. After a few meters is the place which used to be Vriddha Siva-ghata. It is believed that a Siva-linga was found in this area, which is now worshiped behind the birth site of Sri Caitanya Mahaprabhu. This Siva-linga is called Vriddha Siva, or Kshetrapala, the protector (guardian) of the holy dhama. One should worship the merciful Lord Siva to obtain the blessing of devotional service to the Supreme Lord. During the time of Lord Caitanya, a temple of Vriddha Siva existed at this place but was later covered by the Ganga. This is where the Praudha Maya energy (yoga-maya) eternally resides. There are two Sivalingas at this small temple inside the Yoga-pitha campus. One of the lingas was found near the culvert at Mayapur Polyclinic. That place is now known as Siva Doba.
Directions: Turn right ouside the ISKCON main gate and proceed down Bhaktisiddhanta Road. Just after the first turn in the road there is a small bridge and just after that is a path on the left side of the road where you will see some houses. This is the area of Vriddha Siva-ghata.