Beacons are fires lit on hills or high places, used either as
lighthouses for
navigation at sea or for signalling over land that enemy troups are approaching, and alerting the defence. In the latter form, beacons are an ancient form of
optical telegraph and always used in
relay leagues.
In modern technoparlance, a beacon can also be a radio transmitter used for navigation.
Beacons have often been abused by pirate?s. A fire at a wrong position was used to direct a ship against cliff?s or beach?es, so the loaded good could be robbed afterwards.