Nil Diya Pokuna in Karandagolla Cave

Karandagolla Cave or Nil Diya Pokuna (lit: Blue Water Pond) is a tunnel and an underground cave with a pond located in Ravana Ella Sanctuary in Karandagolla near Ella in Badulla District, Sri Lanka. The pond which is called Nil Diya Pokuna due to its natural blue appearance lies about 52 m deep inside the tunnel complex. It has been found out by divers that there are two more tunnels branching off the bottom of the pond. As both the water and the air are fresh inside the tunnel complex, it can be assumed that this underground system is connected to the outer environment from somewhere. 

Merely due to the mystic ambience around this place, locals have tended to believe that this place has a history linked with King Ravana, a mythical figure depicted in the Indian epic Ramayanaya. However, the authenticity of the Ramayanaya is controversial and hence it is today dismissed as a myth by Sri Lankan scholars (JRASSL, 2014).

References

1)  JRASSL, 2014. Journal of the Royal Asiatic Society of Sri Lanka New Series, Vol. 59, No. 2, Special Issue on the Ramayana (2014). https://www.jstor.org/stable/i40203619. pp.1-112.