A lahar is a destructive volcanic mudflow that occurs when volcanic ash and debris mix with water, often from heavy rainfall or melting snow. These flows can travel rapidly down the slopes of a volcano, carrying large amounts of sediment and rocks, which can cause significant damage to infrastructure and landscapes. Lahars can occur during or after a volcanic eruption, posing a serious threat to nearby communities. They can vary in size and speed, and their impact can be devastating, as seen in events associated with Mount St. Helens and Mount Pinatubo. Proper monitoring and early warning systems are essential for minimizing risks.