Roman imperial soldiers built a garrison, on the hill in what is now the old quarter of the village, and constructed a bridge over the river which remains in use.

The origin of the modern name, Iznalloz, has its roots in the Arabic Hisn Allauz which means ‘castle of Almond trees’.

Only the ruins of the castle remain, but it formed part of the front line of Muslim defense during the latter days of the reconquest of Spain.

Due to the growing population of workers, and their importance to the local economy, the Reyes Catolicos (Catholic Monarchs) decreed the construction of a hospital to care for the infirm.

The local mountain range of Sierra Arana is particularly picturesque and boasts a large number of caves.