A lan mine is an explosive device designed to be placed on or in the ground to explode when triggered by an operator or the proximity of a vehicle, person, or animal. The name originates from the practice of mining, where tunnels were dug under enemy fortifications or forces. These tunnels ("mines") were first collapsed to destroy fortifications above, and later filled with explosives and detonated. Land mines generally refer to devices specifically manufactured for this purpose, as distinguished from improvised explosive devices ("IEDs").