It is said that Sri Rama introduced the Siva Lingam here to give penance for the wrongdoing of executing Ravana, a Brahman. He chose this delightful valley encompassed by slopes and verdant greenery for the reason and requested Hanuman to bring a Sivlingam from Varanasi. 

Hanuman was late in showing up with the Siva lingam and as the favorable hour was approaching, Lord Siva himself showed up before Sri Rama and introduced a Sivilingam for establishment. Consequently, the lingam in the sanctuary is called Swayambhu Linga. It is additionally called Ramalingeswara as master Sri Rama had introduced the lingam. 

Hanuman got back with 101 lingams for choice from Varanasi and felt oppressed at not having his lingam introduced. Henceforth he tossed them everywhere on over the zone. Indeed, even right up 'til today a few lingams are discovered dispersed everywhere outside the sanctuary. 

To placate Hanuman, Sri Rama appointed that priority would be given to him for love at the sanctuary. He likewise said that the hillock where the lingam was introduced would bear his name kesarigiri that is, Hanuman, the child of Kesari. Over some undefined time frame, it has casually changed and is presently referred to as Keesara and the slope as Keesaragutta. From that point onward, the customs follow the order of Sri Rama.