The crater lake 'floating' temple of bali dates back to the late 1663 and is situated on the edge of lake Bratan in Bedugal. This water temple used for worshipping the Hindu trinity Brahma-Vishnu-Shiva and Dewi Danu the water goddess of Balinese Hindu's, lies  just north of Bali where the weather is cold and the villas have fire places. 

Water is vital to the Balinese, so much so that the form of Hinduism here is known as Agama Tira, where each time water branches into a different area, a pura trite (water temple) is constructed on the divergence. The balance of elements is very important and priest follow the traditional Tri Hita Karana  (3 causes of wellbeing or  3 reasons for prosperity) for the islands prosperity as a whole, stable development, environmental practices and the overall quality of life for all.  It also symbolizes the  trinity that goes between human and god, humans and nature and humans with society at large or humans and humans.

Tradition according to the chronicle of Mengwi or palm leaf manuscript, states that the location of the Ulun Danu lake Bratan temple built by I Gusti Agung Putu, ruler of the Kingdom of Mengwi, has been used for religious rituals since the megalithic era (rought 500 BC) with artifacts of a stone sarcophagus and board placed above each 'babaturna' or terrace. Its also considered one of the 9 directional temples that protect the island from evil spirits. 

While bathing is forbidden it is only here that you can get a certain type of holy water, where temple priests say the lake is fed by springs located at each of the wind directions. Ulun Danu temple complex consists of 4 temples, those temple are: Lingga Petak temple, Penataran Pucak Mangu temple, Terate Bang temple, and Dalem Purwa. Komang Gede explains "(the) temple serves to adore the majesty of God in its manifestation as the god of Tri Murti, in order to invoke the grace of fertility, prosperity, human well-being and for sustainability of the universe."

Palebahan Pura Tengahing Segara is part of the the Pura complex that is most visible with the 11 stacks of palm fiber roof also call "Meru". This purr is the place to worship the goddess of the lake as well as her residing place. There is also a stupa in the area used by buddhist to pray to Siddharta Gautama, it's existence proving the long time harmony between religions.