Castro-Urdiales

The area around Castro-Urdiales has been inhabited since prehistory. Cave paintings in several local caves, Peña del Cuco, Urdiales, La Lastrilla, La Dársena, and Macizo de Juan Gómez, survive alongside archaeological remains, and pre-Roman hill forts have been identified at Peña de Santullán, Cotolino, Monte Cueto, and Punta del Rebanal. Human activity may go back to the first millennium BC, when the Sámano valley was home to a pre-Roman tribal group, the Sámanos, part of the broader Autrigones people.

Pliny the Elder mentions their port, Portus Amanum, in his Natural History. The tribe fished, farmed, and kept livestock, and left behind bronze and iron ceramics, wheat remains, shells, and a 14 cm bronze sculpture known as the "Cantabrian Neptune," which appears to show a figure holding a dolphin and possibly a trident. In AD 74, the Roman emperor Vespasian established the colony of Flaviobriga on this territory, a name with a clearly Celtic root, giving it jurisdiction over nine cities.

Historical records then thin out until 1037, when the area was absorbed into the Kingdom of Pamplona. In 1040, García Sánchez III of Pamplona gave the territories of Sámano and Castro to his wife Estefanía as a wedding gift. By 1102 a document names the settlement Castrum Ordiales.

In 1163, Alfonso VIII of Castile granted it the status of a town under the Fuero of Logroño, making it the first town on the Cantabrian coast to receive this privilege, Santander would not receive it until 1187, and Laredo later still. The decision was reportedly suggested to the king by Lope Díaz de Haro, former lord of Vizcaya. Through the Middle Ages, Castro-Urdiales was a working maritime town: its Sámano shipyards on the Brazomar river built vessels, and its people fished, hunted whales, and contributed ships and men to Castile's navy during the Reconquista.

The most eye-catching building in town is the Ocharan complex, a palace, a castle-observatory, and gardens, protected as heritage since 1985. The Palacio de Ocharan, also called Toki-Eder, was built in 1901 by local architect Eladio Laredo in an eclectic style. It has a colonnaded portico with Greek-influenced detailing and a decorative frieze of multicoloured tiles designed by Daniel Zuloaga.

The castle-observatory next to it came thirteen years later, also by Laredo, this time in a neo-Gothic style, and stands on Calle Leonardo Rucabado. Elsewhere in town, the Casa de los Chelines on Plaza de España is another neo-Gothic building, designed by Severino Achúcarro and built under the direction of Leonardo Rucabado in the early twentieth century. It is privately owned and was declared a cultural heritage asset in 1991.

Rucabado also designed the Casa Sotileza, known locally as Chalet Sotileza, at the start of Brazomar beach, which has since been converted into housing. Other listed buildings include the Casa para Isidra del Cerro and the Chalet de los San Martín, as well as the municipal cemetery at Ballena and a mineral loading dock at Mioño. Further afield, in the hamlet of Allendelagua on a hillside, stand the ruins of a medieval tower that once belonged to the Knights Templar.

The tower is currently in poor condition.