This 15th century building is located in the church of Santa Mariña de Castrelo. It dates from the 16th century and is made up of three sections, the first rectangular with a niche, the second is a platform used to light a fire as a luminous signal and to house bells as an acoustic signal and the third is a small front with a slab cornice that formerly housed a pinnacle, which has now disappeared. Its function was to summon the neighbours of the area to worship and to the general meetings of the mountains, as well as to sound the alarm if the incursion of bands of assailants was detected, especially during the Carlist wars. In the area around the church of Santa Mariña de Castrelo there is a unique cross with an image of the Virgin with a sword stuck in it.