Five kilometres north of Penelokan, Pura Ulun Danu Batur is the second most important temple on the island after the Besakih complex, and one of the highly venerated directional temples, Kayangan Jagat, this one protects Bali from the North. It's fascinating temple to visit at anytime. As there are usually pilgrims making offerings or praying here, and the mist that frequently shrouds the area adds to the atmosphere, with grand structure looming out of the clouds. The eleven day odalan festival is particularly spectacular and attended by people from all over the island.

The original temple was located down in the crater until the 1926 eruption of Gunung Batur destroyed the whole of Batur village. Shrines and relics that could be saved were taken up onto the crater rim and the village and temple were rebuilt. The present temple structure are quite modern (inaugurated in 1935), and construction is still underway, with more than 90 shrines completed out of the planned total almost three hundred. The temple honours Ide Batara Ulun Danu the goddes of the crater lake, who control the water for the irrigation system throughout the island and shares dominion of Bali with the guard of Gunung Agung. The reverence in which the goddes is held is underlined by manuscript in temple which proclaimed: "Because the Goddess the waters flow, those who do not follow her laws may not possess her rice terraces."

The temple is very different from any other in Bali in several respects. A virgin priestess of the temple selects 24 boys who will serve the goddess as priests in the temple for life. The most important priest, the high priest, Jero Gde or Sanglingan, is selected by the virgin priestess, and is believed to be the earthly representative of the goddess of the lake. His days are spent making offerings to her on behalf of the many pilgrims who come the temple, and at night he dreams under her guidance. Any farmer or Subak with plan that may affect the flow of the water in their area, or who are in comnflict with others about irrigation system come to confer with the Jero Gde, whose word in accepted as final.

With two extra courtyards to the right of the traditional outer, middle and inner ones, Pura Ulun Danu Batur is completely overwhelming for most visitors, simply because of the sheer number of shrines. Most significant is the eleven roofed Meru in the inner courtyard dedicated both to Dewi Danu, the goddess of the lake and to the god of Gunung Agung. On the left side of the middle courtyard is rather unusual shrine, tended by local Chinese community. Dedicated to Ratu Gde Subandar, the Great Lord Harbourmaster and storekeeper for the gods, it's likely that this image dates back to precolonial times when each king had a harbourmaster or trading master who was often Chinese. Most of the other shrines are either dedicated two particular god or honour the deified ancestors of particular ruling houses or clans. The kulkul tower in the outer courtyard to the left houses a drum that is beaten 45 times each morning to honour the 45 deities worshipped in the temple.