Castle of Gerga

Castle of Gerga, above the village of Unzué/Untzue in Navarre, northern Spain, is a rock castle perched on a steep outcrop that once formed part of the defensive network of the Kingdom of Navarre.

What is the Castle of Gerga?

The fortress, also recorded as Guerga, dates back to the 11th–12th centuries and was one of roughly a hundred strongholds that protected the Kingdom of Navarre until its annexation to the Crown of Castile in 1512. Perched at around 990 metres above sea level in the Sierra de Alaiz range, the castle controlled one of the entry points into the southern basin of Pamplona and kept visual contact with neighbouring fortifications. Alongside its military role, it also served as a prison during parts of the medieval period. After centuries of neglect and structural decay, the site has in recent years become the focus of a sustained archaeological and conservation project led by archaeologist Iñaki Sagredo of Gestión Cultural Larrate.

What will you see on site?

The castle's original layout included a square keep with a slate roof, a surrounding defensive wall pierced with arrow loopholes, a water cistern, a chapel, a cellar, a stable and a kitchen. Conservation campaigns carried out between 2020 and 2023 focused on consolidating the keep and uncovering the cistern (aljibe), work that has helped clarify the original arrangement of the buildings. Today the site is largely ruined, but the outlines of the walls, the foundations of individual rooms and the bare rock on which the fortress was built are all still visible. Its position on an exposed rocky outcrop also gives sweeping views over the surrounding hills and valley.

How do you get there?

The castle stands in the Sierra de Alaiz range, close to the village of Unzué/Untzue. Access is on foot, via a trail that climbs from the village up the rocky slope; the ground is uneven in places, so sturdy footwear and a reasonable level of fitness are recommended. Because the fortress sits on a steep rock outcrop, parts of the route involve a noticeable climb.

When is the best time to visit?

Given the exposed hilltop setting, spring and autumn are the most comfortable seasons for the walk, offering milder temperatures and good visibility. Summer heat can be intense on the unshaded outcrop, while winter rain can leave the rocky path slippery.

Frequently Asked Questions

How old is the Castle of Gerga? Its current structure dates from the 11th–12th centuries, although the fortress was rebuilt and reinforced repeatedly over the following centuries of use.

What was the castle used for? It formed part of the defensive system of the Kingdom of Navarre, guarding access to the southern basin of Pamplona, and it also functioned as a prison during certain periods.

Is the castle well preserved today? The site remains largely a ruin, but conservation work carried out since 2020 has uncovered and stabilised further elements, including the cistern and the remains of the keep.

Is the walk to the castle difficult? The approach follows a rocky, uneven trail with a noticeable climb, so it should be treated as a hillwalking outing and approached with proper footwear.