The Celtic Settlement of Ulaca is located on top of mountain of difficult access, strengthened further by a wall of 3 km. long.

Is undoubtedly the most impressive of the Vettones Settlements and one of the fortified Celtic cities more important of all over Europe.

It occupies a large granite mountain over 1,500 meters high. From its summit can see wide views in all directions, especially towards the north, then dominates Amblés Valley, and south, where stands the majestic mass of the Sierra de la Paramera. Surely, that would be a shrine to pressure Roman fortified and became a major fortified city, which seems to have dropped to 72 a. c., probably as a result of the Wars Sertorianas.

It offers more than 60ha in area, with several major enclosed by walls of more than 3000 meters in perimeter and reinforced with some additional lines, but quite devastated. Inside the village, carved into the granite rock, is one of the best preserved in the world of spiritual and cultural vettones known as the "Altar of Sacrifice" is a compound of irregular plant chaired by a prominent rock the immediate environment, which has built a double staircase, all culminating at the top in several cavities to be interpreted as time-related rituals of sacrifice. In addition to the "Altar" The Castro, in his interior retains many foundations of houses and some very unique monuments such as the "Fragua" certainly remains a sauna ritual carved into the rock, the "Tower", a set of large blocks belonging a large public building erected next to the main village, and several pre-Roman quarries that are still in situ of the blocks as they were uprooted.

Bear witness to the culture vettona developed in the Castro, zoomorphic sculptures, known as boars found in the vicinity and is currently facing a church Solosancho, 2 kms from Robledillo and Castle delantedel Villaviciosa.