The blue god Upulvan or Vishnu is the guardian god of Sri Lanka. It was believed that god Upulvan blessed the North Indian prince Vijaya and his followers upon their arrival to Sri Lanka during the 6th-century BC. This is the main shrine in the island dedicated to god Upulvan, hence it is painted in blue.
Chronicles suggest that during the medieval times the entire Dondra area was owned by the temple. Ibn Battuta, the medieval explorer who has travelled more than anyone else, and Zheng He had visited this temple.
In 1587, during the Portugese era the temple was completely destroyed and a lot of its stoneworks were sunken in the sea. However recent excavations have unearthed a Shiva Lingam and a sculpture of Nandi Wrushaba suggesting that the temple has been a sacred place for Hindus.
The temple can be seen on your right hand side when travelling from Matara to Tangalle. You’d be required to wear appropriate clothing and walk barefooted while visiting.