Castillo del Xinquer is a medieval fortress in ruinous condition situated next to the abandoned hamlet of Xinquer, in the municipality of Alcudia de Veo, in the province of Castellón. It is located within the Sierra de Espadán, in a mountainous and difficult to access environment.

Available data on its history is scarce, although its typology and location place it within the set of territorial control castles built during the period of conquest and Christian repopulation in the 13th century in Valencian lands. Its name derives from the homonymous hamlet that surrounds it, now depopulated.

The complex is in an advanced state of deterioration. The original architecture can barely be appreciated due to the collapse of its structures, with only vestiges of the perimeter walls and fortifications remaining that allow one to infer its original layout.

Access to the castle is from the nucleus of Alcudia de Veo, crossing the rural paths that penetrate into the sierra. Its natural surroundings, within the Sierra de Espadán Natural Park, add scenic value to the visit.

The Xinquer hamlet, equally abandoned, constitutes another element of heritage interest in the immediate surroundings of the castle, evidencing the rural depopulation that affected many inland villages in Castellón during the 20th century.