Free visit of the lookout at the Crulière
Lookout: This name was usually given to optical stations. He probably also applied himself to monitoring posts (formerly customs posts). Between the eighteenth and nineteenth centuries, here stood an optical telegraph station, long destroyed. It was in 1792 that Claude Chappe, a French engineer, proposed to the Legislative Assembly a communication system based on the transmission of messages between stations spaced about ten kilometers and located on high points. The messages consist of a series of semaphore signals which, read with a telescope from the previous tower, are reproduced to be read from the next tower. Thanks to this process, messages only take a few minutes to reach the other end of the territory. It was in 1794 that Claude Chappe established a first connection between Lille and Paris.