The main attraction for visitors is located around Lake Batur where Penelokan village provides spectacular views of this crater lake and Mount Batur, set in a vast volcanic caldera. Photo opportunities abound, but try to be there as early in the morning as you can manage before the cloud inevitably starts to gather.
Further northwest along the rim of the caldera is Pura Ulun Danau Batur, one of the most important temples in Bali. Entry is by donation here – Rp 10,000 is about right. The temple was rebuilt up on the caldera ridge in 1926 after an eruption of Mount Batur destroyed the old one down in the crater. There are a large number of shrines, but most visitors are drawn to the huge eleven roofed meru in the inner courtyard. This is dedicated to the goddess of the lake, Ida Batara Dewi Ulan Danau who is regarded as the controlling deity of the whole water and irrigation system of Bali. A virgin priestess is resident at the temple to represent the goddess, and she is served by 24 priests who are chosen as young boys and then keep the role for their lifetime. This is a strong example of just how importantly water and irrigation matters are regarded in traditional Balinese culuture.
You can visit the Bali Aga village at Trunyan on the eastern shore of the lake by boat from Kedisan. This is recommended in some guides, but first hand reports are frequently negative and speak of some problems. This is an isolated community and one which is not particularly welcoming to tourists, despite relying on income from visitors. If you really must go, catch a boat at the lakefront in Kedisan (or you can charter a boat from Toyo Bungkah) and make sure the price is clearly understood before departing, and that the entrance donation to the Trunyan villagers is included. When you arrive at Trunyan, the key attraction is the cemetery. Ancient customs retained by the Bali Aga here include the open burial of dead bodies in a pit covered by just some light cloth. If you want to visit a Bali Aga village though, then Tenganan near Candidasa is a far better option.
One of the best things about a visit to Trunyan is the views of Mount Batur from the eastern shore of the lake. This provides a very different perspective from the usual view from the crater rim. You can though get those same views by taking the small road around the southern edge of the lake through the villages of Kedisan (where there are a few simple places to stay and eat), Buahan and on to the tiny settlement of Abang. The road ends at Abang, a four wheel drive vehicle is more appropriate for this skinny and at times very steep road(but you can explore the eastern shore of the lake further on foot, all the way to Trunyan (about 4 km) if you are feeling energetic (you will be stopped by locals along the way asking if you want to go to Trunyan, they may even follow you and tell you that you cannot go there on foot and you must take a boat with them. Take plenty of water for the walk and be prepared for steep hills.