The most obvious feature of the Buyan-Bratan volcanic complex in north-central Bali is the 11 x 6 km wide Bratan caldera (also known as Catur or Tjatur caldera), which contains three caldera lakes. Several post-caldera stratovolcanoes straddle its southern rim; the largest post-caldera cone, Batukau (Batukaru), is 10 km SW. The cones are well-formed, but covered with thick soils and vegetation; they are thought to have been inactive for hundreds or thousands of years (Wheller, 1986). The Tapak and Lesong cones are not covered by deposits of the youngest dacitic pumice eruptions of nearby Batur volcano, and are thus thought to be less than 23,000 years old. Read more about Buyan-Bratan caldera at Global Volcanism Program