Watchtower
Half way through the XVII century military conflicts with Portugal forced the reinforcements of the defences of Monterrei. New keeps were built surrounding the castle, a watchtower (in 1664) 550 m to the north-east, to defend the fountain and the access from the north-east .They also constructed the fort of San Salvador, taking the form of a star with five points that was started in the Coto da Esculqueira mountain range, at 695 m high. The construction of this fortress that was probably never finished was destroyed by mistake in the second half of the XX century. Between the watchtower and the castle, 350 m to the East, is the location of the fountain built by Count Alfonso of Acevedo, grandson of the archbishop Fonseca from Santiago that also gave him the town. His orders prohibited people to wash in the fountain “clothes or intestines”.