Gheriat eal-Garbia: Roman fort in Libya, part of the Limes Tripolitanus. The signal tower discussed on this page, was part of its lines of communication to the north and east.
About a kilometer from the Roman fort at Gerhiat al-Garbia, to the northeast, are the remains of an ancient signal tower, which once connected the fort with other military settlements. Both light signals and smoke signals were possible. The soldiers who occupied the tower, must have belonged to the garrison of the fort itself.
The tower, built out of natural stone that was locally quarried and cut, is known to archaeologists as GG7 in the catalogue of Graeme Barker e.a., Farming the Desert (1996). Through this tower, the oasis of Gheriat al-Garbia was in signalling contact with the centenarium of Gheriat esh-Shergia and to the north.