Deserted belonging locality to municipality of Sigüés in the altoaragonesa region of the Jacetania. Located in an environment privileged in full marsh of Yesa on one foreland that he speaks to us about his ancient defensive past. Of what was the ancient Town only the high part of the same one stays since her fall has disappeared under the waters, as most of his term, together with those of Escó and Ruesta. The construction of marsh led to the abandonment of the Town, for the expropriation of his gardens and grounds of cultivation, as well as of his water spa sulphurous, that sprouts to a temperature of 35ºC.

The parochial church of the XVIIIth century with dedication to San Miguel presents a plant of Latin cross with testero rectum, beautiful dome on scallops in the cruise and tower to the feet, where there survive the only Gothic remains of a previous Gothic construction.

Tiermas is much known in the last years for transforming into one unexpected natural spa when one dismisses the summer. Although it should treat about a deserted Town Tiermas it is provided with camping service nailed in a beautiful place making his visit more accessible. (fte and texts to see links)