Lake Batur fills part of an enormous volcanic caldera in north-east Bali, and the first view of it, from the rim at Penelokan, is one of the island's best. The word Penelokan means a place to look, and the sight justifies it: a huge crescent of dark water about a thousand metres up, with the active cone of Mount Batur rising from the crater floor, and beyond it the bigger bulk of Mount Abang. A bigger sibling, Mount Agung, stands to the east, and at over three thousand metres it is the island's highest and most sacred peak. Batur itself last erupted in the early 2000s, and lava flows from earlier eruptions are still visible as black fields on the slopes.
The caldera is a place of holy things as well as geology. The temple of Pura Ulun Danu Batur, on the rim, honours the goddess of the lake, who is believed to provide water for the whole island's rice fields, and is among the most important on Bali. On the far shore, the village of Trunyan has an unusual way of treating its dead, and below the rim, at Toya Bungkah, hot springs bubble up for bathing. Local hikers lead pre-dawn walks up Batur for sunrise, and the crowds can be large.
The roads here are a pleasure. The route along the rim and down to the lake is cool, misty and green, with long gradual bends, tight hairpins and views that open and close in clouds. In the morning it can be glorious, with low sun on the water, but by noon cloud often rolls in and the temperature drops, so bring a jacket. The surface is mostly good, though trucks carrying vegetables and tour minibuses crowd the narrow sections, and sellers at the viewpoints can be persistent.
The nearest big towns are some distance away, Bedugul about thirty kilometres to the west and Klungkung a little further south, and the villages on the rim have little in the way of services, so begin with a full tank. Roadside warung and a few lakeside restaurants offer fried fish from the lake, corn, noodles and strong coffee. Mist, rain and slippery roads are common in the wet season, from November to March, and the dry months bring clearer views. Keep a layer ready for the evening descent.