The Mosqueiro redoubt is also part of the 2nd Line and is one of a group of fortifications that, with the Ribas hills, formed a barrier against the invaders’ advance. It is polygonal and surrounded by a deep trench that makes a good walk. The height of the counterscarp still imparts a sense of security to anyone protected by it.
From here, you can see the Cabeço de Montachique, the highest point in the municipality and the remains of a volcanic chimney. A Signals Station was established here during the French Invasions. The defensive system was not just a network of military roads that assured allied supply routes and troop movements, but also a communication system based on optical semaphore.