An imperturbable 26.5-metre sentinel stands there on the hill, witness to the changing worlds over the centuries. Its appearance, too, has not always been the same. Built in 1320, it was given the daunting task of defending and communicating from the highest point of Viarigi, along with a well-designed path involving the surrounding ridges.Its name is a sign of its ancient arts: we are in the presence of the so called Torre dei Segnali, the Signal Tower, praised in the verses of Agostino della Sala Spada as a "quadra torre, sovra l'arduo colle" (square tower, over the arduous hill). In the mid-1800s, each side of the square was clad in bricks to make it more durable. A century later, the wooden staircase that used to fill the interior, worn out by time and use, found a steel replacement. Countless works changed its aspect. Looking up, we see it crowned with Ghibelline 'swallowtail' battlements, a sign of loyalty to the empire. Just above are four arched cornices, which were familiar features of the towers of the time. We walk in through the only access we have today: the brick and tuff construction beside the tower, after the hearth we find a metal ramp to access the guardhouse terrace. Inside, the vaults are barrel vaulted, with bricks laid flat and cut, affected by the wear and tear of the years.