A watchtower is a type of fortification used in many parts of the world. It differs from a regular tower in that its primary use is military, and from a turret in that it is usually a freestanding structure. Its main purpose is to provide a high, safe place from which a sentinel or guard may observe the surrounding area. In some cases, non-military towers, such as religious pagodas, may also be used as watchtowers.An example of nonmilitary watchtower in history is the one of Jerusalem. Though the Hebrews used it to keep a watch for approaching armies, the religious authorities forbade the taking of weapons up into the tower as this would require bringing weapons through the temple. Rebuilt by King Herod, that watchtower was renamed after Mark Antony, his friend who battled against Gaius Julius Caesar Octavianus (later Augustus) and lost.