Lightning rod is a device that protects homes and other buildings from damage by lightning. A common type has a metal rod installed on top of a building. A wire or cable leads from this rod to a ground rod buried 10 feet (3 meters) or more in the earth. The ground rod should be buried at least 2 feet (61 centimeters) from the building in moist earth. It should be as straight as possible. If a building has several metal supports, each should be connected to a lightning rod and there should be several ground connections.