The paper examines a particular and little-known type of fortified landscape, the coastal defense and control network built in the Napoleonic period along the Adriatic coasts. The system included defensive posts as coastal batteries and the optical telegraphic or semaphoric line based on the aerial telegraph invented by Claude Chappe and then adapted for the maritime communications by Charles Depillon. The first terrestrial telegraphic line was activated in 1794 between Paris and Lille and the communication network extended all over Europe in the following years, being an essential instrument for the Napoleonic wars. In 1810 the Paris-Venice line was completed. On the Adriatic coast, the telegraphic line ran from Istria to the Marche, where it was linked to the similar network of the Kingdom of Naples. The telegraph posts were located in existing fortified elements or in the small coastal batteries, built along the coast or at the mouth of the rivers. Thanks to the recent reopening to the consultation of the archive of the Marina Regia at the State Archive of Venice it will be possible to reconstruct the genesis and the realization of this network in order to verify the exact position of the posts and their state of conservation. Given the extreme vulnerability of the structures, often consisting of a simple embankment located in areas currently of tourist-seaside interest, many forts have disappeared, but the identification of their position will allow the protection of any surviving remains. In the case of telegraphs built on existing buildings, such as coastal towers, bell towers or forts, the reconstruction of the communication network and therefore of the close relationship that these artifacts had between them and with the territory will still be interesting. The matter is of considerable interest and potential for development even at the national level, as the telegraphic network involved all the coasts of the peninsula and islands and, although the Napoleonic line was dismantled in 1814, the semaphoric network was then again used throughout the nineteenth century. In particular, also the numerous ancient sighting towers scattered along the southern coasts were often used as telegraphic or semaphoric stations in the second half of the nineteenth century.
