The Telegraph of Castellbisbal Monument · Castellbisbal, Vallès Occidental, Barcelona Image of Castellbisbal, not of the place itself. El Telègraf, or Torre Fossada, is a tower of a former optical telegraph line in the municipality of Castellbisbal (Vallès Occidental), declared Bien Cultural de Interés Nacional (Spain's highest level of heritage protection). Situated above the crossing of the Llobregat river, next to the Pont del Diable, it has a square floor plan, about 5 meters on each side and 7 meters high, with two floors and a flat roof, and it was surrounded by a moat crossed by a platform with a drawbridge. It was built in the mid-19th century as part of the military optical telegraph line from Barcelona to Lleida, communicating with the towers of Molins de Rei and Esparreguera. On 24 January 1939 it was one of the last points of resistance of Republican troops against Franco's army; it was restored by the town council in the mid-1990s. Photo: Pere López Brosa (CC BY-SA 4.0) What to see and do in Castellbisbal