Siero, Asturias: municipality guide

Siero is a municipality in central Asturias, the fourth most populous in the region and a key part of the Central Area of Asturias. Its capital is La Pola Siero. With 53,049 inhabitants and 211.23 km², it combines rural meadows and plains with a powerful industrial and commercial fabric, just 18 kilometres from Oviedo.

What to see in Siero

The jewel of its religious heritage is the Romanesque church of San Esteban de Aramil, from the 12th century, with a single nave, a semicircular apse and finely carved corbels. In the capital, the 19th-century parish church of San Pedro and the church of San Martín in Argüelles, with pre-Romanesque elements, complete the sacred itinerary.

Romanesque church of San Esteban de Aramil, in Siero. — Photo: Wikimedia Commons / Hernantron (CC BY-SA 4.0)

Among the civil heritage stand out the bridge of Colloto, of Roman origin, spanning the river Nora and marking the historic boundary with Oviedo; the Palacio del Marqués de Canillejas in Valdesoto, declared a Cultural Interest Asset; and the palaces of Meres and Argüelles, witnesses of the medieval lordships that settled the municipality.

Colloto bridge over the river Nora, in Siero. — Photo: Wikimedia Commons / Adolfobrigido (CC BY-SA 3.0 es)

The mining heritage has its own route: the Siero mining route runs past the headframes of Pumarabule, Mosquitera, Candín and Solvay, metal giants dominating the southern part of the municipality. The festive, commercial Siero is embodied by the livestock market of La Pola, a pioneer and leader in Spain, and by the residential town of Lugones, the most populous locality of the municipality. Siero is also the third Asturian municipality with the most cider presses (llagares).

All of this just 18 kilometres from Oviedo, making Siero a perfect day trip from the Asturian capital.

Getting there

The A-64 (Oviedo–Villaviciosa), the A-66 (Ruta de la Plata), the AS-I (Mining Motorway) and the N-634 cross the municipality, connecting it with Oviedo, Gijón and the mining basins. Renfe Cercanías lines of both Iberian and metric gauge also run through Siero. La Pola Siero is 18 kilometres from Oviedo.

Map of the municipality of Siero: the capital, in gold. Data © OpenStreetMap (ODbL).

Festivals and gastronomy

The main festival is El Carmín, on the Monday after 16 July, one of the most crowded celebrations in Asturias. On Easter Tuesday the Fiesta de los Güevos Pintos (Painted Eggs Festival) takes place, declared of National Tourist Interest in 1968, with hand-painted eggs bearing Asturian motifs. Les Comadres, on the Thursday before Carnival, is a festival with a marked gastronomic character, and Les Carroces de Valdesoto are a Festival of Regional Tourist Interest. On the table: cider from the local llagares, dairy products —the Central Lechera Asturiana is headquartered here— and classic Asturian dishes.

Municipality facts

Coat of arms: Wikimedia Commons / SanchoPanzaXXI (CC BY-SA 4.0)

Capital: La Pola Siero
Population: 53,049 inhabitants (INE 2025)
Area: 211.23 km²
Zone: Central
Demonym: sierense
Town Hall: Plaza del Ayuntamiento, s/n, 33510 La Pola Siero. Tel. +34 985 72 54 24