The Japanese Cave is a wartime tunnel complex in the Dago hills, built during the Japanese occupation in 1942. It was created with forced labour and used as a defensive shelter, so it is a sombre rather than scenic stop.
Bring a light if you plan to go inside, and combine it with other Dago sights such as Curug Dago or the viewpoints above Bandung. The short visit is most worthwhile for travellers interested in World War II history in Indonesia.