The inscription "CORDEIRO DE 1759" can be read on the lintel of the access door to the patio, which does not necessarily mean the date of construction of the house, since there are documentary references that cite the Avalles as residents of this parish. of Corzáns in the 16th century.

This House-Tower built the same Sarmiento that ruled the Sobroso and the Valley of the Chips. Near Petán is the Chapel of "Nosa Señora do Carme", which houses burials of the lords of Petán with inscriptions and weapons of the Sarmiento and Pereira de Castro (alluding to Diego and Julián Pereira de Castro y Avalle, from the year 1752, and fringed with flags, pikes and other military insignia).

There are two architectural components of the Casa-Torre de Petán to highlight:

  1. The wide panel of which the portal is part, of good ashlar and finished by a cornice molded with pyramidal ball pinnacles. Above the gate is a carefully worked shield crowned by a stone cross between pinnacles. The Petán path ran outside the wall, which people say was the path that went to Madrid.

  

  2. The other component is the same tower, which stands at one end of the building. It has a square plan, with angular gargoyles of drainage in the form of cannons and battlements, between which are interposed pyramidal auctions similar to that of the Portalón. Inside, a large double arch supports the upper floor, which is accessed from a nearby patio by a stone staircase attached to the tower wall.

The coat of arms of the gate represents the heraldic insignia of the Sarmiento, Ozores, Sotomayor (perhaps Valladares) and, possibly, Marino. Above the coat of arms is a large bolada-shaped crown in which the thirteen Sarmiento roles are repeated, while lambrequins decorate the entire outline.

The state of conservation of the building is uneven because it is divided among three families. The left part, immediately next to the tower, is being restored.