The church of La Asunción in Canfranc was given to the St Christina Monastery in Somport by the Aragonese king Pedro II (Peter II) in 1202. Over the course of its history it has been destroyed and rebuilt on a number of occasions. The last of these was the devastating fire that destroyed the village in 1944 and caused considerable damage to the structure of the church, more specifically to the arches that supported the vaulted ceiling. The church was subsequently rebuilt.

Therefore, its present state is the result of a number of changes made throughout its history. The most important of these were the modifications of the master builder Juan de Segura at the beginning of the 16th century, when it appears that the rectangular main chapel with its star-ribbed vaulted ceiling was built.

The church, of simple but imposing proportions, has three naves. Each of the lateral walls has two chapels. The most singular element of its layout is the octagonal bell tower in the west wing of the building. Also of note is the simple portico with a gabled roof which protects the main entrance.

On the inside, it is particularly worth mentioning the altarpiece of Neogothic style dedicated to Our Lady of the Assumption and made after the 1944 fire in the workshop of the Albareda brothers in Zaragoza. However, two sculptures from the original altarpiece which survived the fire are kept in the attic of the church.

The decoration of the four lateral chapels is also of great interest which all contain Barroque altarpieces saved from the fire by the inhabitants of the village. The first chapel on the Epistolary (right) side holds the altarpiece dedicated to the Holy Trinity. The second chapel has an unusual altarpiece in three parts. In the first chapel on the Gospel (left) side, there is another altarpiece with two levels of three sections each of rough craftsmanship, dedicated to Pedro de Arbués, who was beatified in 1664.

The last Barroque altarpiece, also a in three parts and in this case dedicated to the Holy Family, is in the second chapel on the Gospel side.