The Lembang Fault is an active east-west trending fault about 30 kilometres long located just north of Bandung, a major city of more than two million people in West Java, Indonesia. Its clear scarp cuts across the volcanic highlands near the Tangkuban Perahu volcano, forming a distinct step in the landscape.
The fault is predominantly a left-lateral strike-slip structure and slips at only a few millimetres per year, but its close proximity to a large and rapidly growing urban area makes even moderate earthquakes potentially very damaging. Paleoseismic trenching has revealed evidence of past surface-rupturing earthquakes.
Studies indicate the Lembang Fault has produced significant earthquakes in the past and is capable of generating a future event of around magnitude 6.5 to 7. Because much of Bandung's population lives close to the fault, it is considered one of the most important seismic hazards on the island of Java and a focus of disaster-preparedness efforts.