(VALLIS-CASTELLUM or the Castle Valley).
This village was first mentioned in the 13th century when King Alfonso IX donated it to the monastery of Valdedios.
In fact, the Cerro de la Sierra was the site of the castle that Alfonso IX, King of León, ordered to be demolished because it was held by King Alfonso VIII of Castilla.
The Sierracastillo hermitage was also next to this castle or tower.
Valdecastillo used to belong to the council of the Villa de Boñar and Vega de Valdedios.
Its magnificent parish church, recently restored, dates from the 16th century and is dedicated to Santa Eulalia. In the centre of the village there is also the hermitage of the Virgen de Lourdes.
Valdecastillo is located 5.1 kilometres from Boñar.
It is famous for its Venta de Remellán and silica mines, celebrating its patron saint festivities on the 4th of September.