Mount Pinatubo is a stratovolcano on Luzon in the Philippines. It is around the Tri- Cabusilan Mountain range, separating Luzon's west coast from the central plains. Before 1991 the volcano was inconspicuous, heavily eroded and covered with dense forest, which had several thousand indigenous people. The volcano erupted in June 1991, destroying thousands of buildings and houses and killing over 800 people. Mount Pinatubo's eruption effects were felt worldwide.