The mystery of Torre de Vallferosa

Torre de Vallferosa, located in the town of Torà, Spain, is a monument declared as bé cultural d'interès nacional. Although traditionally it has been believed that the construction of the tower occurred around 970 AD, recent studies with new techniques suggest it may date to the 8th or 9th century. The tower is one of the best examples of medieval European military architecture. It is a circular structure with a spiral staircase inside, built over an older tower. Merlons adorn the top of the old tower, and some sections of the internal staircase and roof remain from the 4th floor. The exact year of construction is uncertain, but studies suggest that the origin of the tower may have a relation to controlling the ancestral communication routes (transhumance and trade between the interior of the country and the coast) and, consequently, of control fiscal.

Sources: Wikipedia, OpenStreetMap, Wikidata, Wikimedia Commons