The castle at the western edge of town was built in the 15th century as the seat of the Álvarez de Toledo family, who held the title Marquises of Villafranca and controlled much of El Bierzo during the late medieval period. The family's power reached its peak when Fernando Álvarez de Toledo — the fearsome Duke of Alba, general to Philip II — was among its descendants. The castle was a working fortress and noble residence, not merely decorative, and its position above the valley confluence made it an effective control point over the roads running east to Castile and west toward Galicia.
Today the castle is a substantial ruin, not open to the public, but best seen from below on the road approaching town or from the bridge over the Burbia. The remaining towers and curtain walls give a clear impression of the original structure against the sky. It is the kind of ruin that improves with distance — the silhouette above the valley is far more impressive than anything you would see inside.