A primitive Romanesque temple once occupied the site of the church of St Martin in Embún but only one section, known as “the prison”, survived the 16th-century rebuilding work. During this period the interior was extensively modified and the choir gallery and bell tower were added.

The church is divided into three naves, the oldest of which is on the south side and has a barrel-vaulted ceiling. The supports for a rib vault in the chancel date from the 16th-century reconstruction work. The north nave was built in the 18th century and connects with the central nave through two elliptical arches supported by a central pillar.

The doorway, which is protected by a porch, opens into the western end of the church. Its structure shows the influence of the model used in the “Coloma Palace” in Zaragoza, although the latter has since been replaced. This type of doorway became very popular in the Jaca area and was used in other prominent buildings, such as the Town Hall in Jaca itself. It consists of a rounded arch supported by two beautiful Tuscan columns.

The main altarpiece dedicated to St Martin is the most interesting of the pieces inside the church. It is a work of Romanist sculpture dating from the beginning of the 17th century which was subsequently subjected to a number of modifications. Originally it was built on three levels but now only two remain.

Also of great interest are the altarpieces of the Holy Christ from the beginning of the 17th century and the altar dedicated to San Francisco de Asis with two mouldings crowned with female busts in profile, known in the area as the She-devils of Embún. The altarpiece of the Virgen del Rosario dates from the end of the 17th century and contains a 16th-century wooden sculpture. The Rococo altarpiece of St Michael, from the second half of the 18th century, also stands out from the collection.