Despite significant development in the last decade it is still home to the endangered and endemic purple-faced langur, an unusually shy monkey species that can only be found in Sri Lanka's forests.

In the epic, the monkey-warrior Hanuman was sent back to India to fetch the four medicinal herbs by Jambavan namely, mritasanjeevani, vishalyakarani, suvarnakarani, and sandhani from the Himalayas in order to heal Lakshman who was wounded trying to save the abducted Princess Sita from the demon king Ravana.

Hanuman failed to identify these herbs, so he lifted the entire mountain and carried it to the battlefield to try to save Lakshman, but in the process, a chunk of it "fell-down" in the location of the present day Unawatuna, the name of the village derives from "Una-watuna" meaning "fell down".

A banished Indian Prince was shipwrecked and the Goddess of Earth, Manimekalai, taking pity created a rocky shelf for him to save his life and that subsequently he headed to Unawatuna.

Fisher folk save and offer part of their earnings called "Goda kotasa" seeking protection on their forays into the ocean.

The Galle tower or Edward's Pillar on Rumassala Hill is believed to have been a fake lighthouse built during World War I, and the area is shown as property of the British Admiralty in old survey maps.

Off the coast of Unawatuna, beneath the Indian Ocean lies a number of coral reefs, shipwrecks, and a great variety of fish and turtles.

The Rumassala coral reefs at the east end of the Galle Harbor attract divers, but are now endangered due to possible port development.