Medieval watchtowers varied in size but were usually high structures, as the name suggests the towers needed to be high so that the surrounding areas could be watched for attacking enemy soldiers.
Usually, a watchtower or lookout would have a 360-degree view and the watchman or guard could literally see for many miles all around.
Watch towers were used right across the world and date back to ancient times, the Romans built watch towers for their fortifications. The Romans used a network of watchtowers that covered vast areas to control large parts of the Roman empire.
Each tower was visible to the next one along with the network, which created an amazing messaging system to warn other areas of impending dangers, the Romans used semaphore signaling to send messages between the watchtowers.
In early medieval times, the Italians built a series of coastal watch towers, these watchtowers were to warn of attacks from the Saracens and other Muslim threats.