Lakegala is a giant monolith-like projection at the eastern extremity of the Knuckles Mountain ranges with an almost at a 90 degree angle. On the other side there is a sudden drop of over 900 meters. Rawana had one of his abodes on its peak, and that his kingdom of Lankapura surrounded. It was also used as a device like a sundial to calculate time in his kingdom.
In ancient times this rock was known as Lanka Pabbata or Lankagiri. [Rock of Lanka]