The location of Agüero is extremely pictorial and forester, on the hill of a high hillock considerably high with regard to the route of the river Gállego which is closed inside the mountains and in an extensive valley. In the north this valley is enclosed in the spectacular saw called "Mallows of Agüero", with the capricious forms on its mass of conglomerate light red coloured, characteristic of the Tertiary period; very similar to the more known Mallows of Riglos, placed on the opposite bank of the Gállego river. The mallows in Agüero are a spur of the very long saw of Santo Domingo.
      The origin of Agüero like the one of the majority of the places in the craggy fringe started in the reconquest period; there are only some ruins left belonging to the castle, which already existed at the end of the 10th century. We know the name of its ten "tenants" according to some existing documents. These "tenants" took care of it in the XI and XII centuries until its tactician interest ended. As a small historical curiosity we will say that at the beginning of XII century, Queen Berta (she was Peter the first of Aragón's widow) governed from Agüero the mallows kingdom, which included Murillo, Marcuello, Riglos and Ayerbe.
       In the streets of Agüero some houses still have the pureblooded appearance of Prepirineo. Its church is considerably emphasised by its artistic importance and around it is Santiago church where romantic art is always present. The first one, which is dedicated to "El Salvador", is in the main square. What is important in it is its high and quadrate tower of the XVI and XVII centuries with several separated bodies with imposts. It is a church, which has three Romanic naves renewed enough lately. It has the old central nave under a barrel vault, although its semicircular apse was rebuilt in the Baroque period. The wonderful rateable with sculptures belongs to this art. The old crypt is still under the apse (XVI century) The lateral naves were rebuilt in the late gothic period, with starred vaults and renaissancist cylindrical pillars and wide arcades decorated with caissons of the latest style. The most artistic piece is the front opened in the north side of the Romanic nave, which has a porch with some arcs; it is a wonderful composition of semicircular archivolts designed with several designs of Romanic art. Apart from this it has some lateral columns and a superb tympanum with the Pantocrator in the middle of it, circled by the four Evangelist's figures: the angel, the lion, the bull and the eagle.
      In the close governing or abbatial house Sir Louis Galindo Bisquer, who was a Parish priest in Agüero created a very original thematic museum consecrated to the Organ with a great deal of pieces about all types; it is really something unusual and very interesting.
       At about seven hundred metres far from the village, we can find Santiago's church which is a Romanic jewel without any late renewing but it has not been finished yet. It was thought to be a Latin cross plant church but the nave was not built, so it is a very short temple only consisting on the transept and the three semicircular apses of the XII century. The spires and the friezes offer a great decorative richness, mainly the ones on the wonderful front, which also has a sculptured tympanum with the "Adoración de los Magos" on it. The unknown sculptor has received the title of masterwork man of Agüero and the invocation reveals the proximity to Santiago's way.