Kawah Putih is one of the two craters which make up Mount Patuha, a volcano located about 50 km south of Bandung in West Java. Currently, the volcano is not showing any signs of activity and has been open to visitors since 1987.
Kawah Putih is a highly acid lake which changes colour from white to turquoise or green, depending on the concentration of sulfur and the temperature. On sunny days, the colour of the lake is very bright, while on cloudy days the crater is covered in mist. The sand and rocks surrounding the lake are also whitish due to contact with the acid.
The lake is located almost 2,500 m above sea level so it's often quite chilly here. Temperatures may drop to 10°C. The dry season is usually a better time to visit the lake. Also if you visit Kawah Putih when it rains, you might not be allowed to go to the crater. It's possible that the fog contains poison gas from the crater. Therefore May through November is definitely a better period to choose for a visit. However, mind that June and July are very busy months due to school vacations. It's better to avoid this period as well as weekends if you don't want to get stuck in traffic.