Castell de Castellnou d’Ossó: A Roman and Medieval Fortified Castle
Site at a Glance
- Rating
- 5
- Popularity
- Very Low
- Country
- Spain
- Primary era
- Classical
- Eras represented
- Classical, Medieval
- Civilizations
- Roman
- Site type
- Military
- Remains
- Castle
On this page8 sections
History
Castell de Castellnou d’Ossó is a fortified site in Spain, first established as a Roman stronghold in the first century CE. Its fortification may have watched over Iberian communities, including the Ilergetes, an ancient people of northeastern Iberia, in the Sió basin. It may also have helped control the route between Ilerda and Iesso, ancient cities in the region.
Medieval development
Around 1070, Count Ermengol IV of Urgell, a county in what is now Catalonia, conquered the territory. Soon afterward, a medieval tower was built over the base of the earlier Roman tower. Other castle buildings were probably added beside it later.
The castle was enlarged over time. In 1408, its lord, Luis de Santmartí, a noble who held authority over the estate, carried out a reform.
Later ownership and recognition
In 1831, during Spain’s disentailment measures, which involved confiscating and selling property held by institutions such as the Church and municipalities, the site and castle belonged to the Marquis of Dosaigües. A marquis ranked below a duke and above a count.
In 2014, the Llurba-Huguet family transferred ownership to the municipality to enable rehabilitation. A restoration proposal for the castle and its surroundings cited the Roman structure’s distinctive characteristics and its lack of known parallels in Spain. The castle received Catalan Cultural Asset of National Interest status in 1985 and was listed as a Spanish Asset of Cultural Interest on 8 November 1988.
Remains
Castle and adjacent church
The ruins stand on the summit of a small hill on the right bank of the Sió, above the settlement that developed around the site. The remains include a stone enclosure, a tower at its center and the Romanesque church of Sant Pere beside the castle.
Roman enclosure
The enclosure was probably circular, about 24 metres in diameter, with an entrance on its northern side. Its surviving masonry includes very large blocks, carefully shaped with rough-finished faces. The remains preserve the eastern semicircle and a right-angled section in the entrance area.
Medieval tower
The surviving lower portion of the tower is about 4 metres high, though it was probably once much taller. Its eastern face has a large opening about 2 metres across. Inside, traces indicate either a dome-shaped vault or a dome made of rammed earth. A circular opening near the center appears to have provided access from an upper floor, where the original entrance was probably situated.
Church of Sant Pere
The Romanesque church of Sant Pere de Castellnou d’Ossó stands beside the castle.


