Zafra Castle (Spanish: Castillo de Zafra) is a 12th-century castle in the city of Campillo de Dueñas, Guadalajara, Spain. The present castle was built sometime between the second half of the 12th century and the early 13th century on a sandstone outcrop in the Sierra de Caldereros, on the site of a previous Visigothic and Moorish fortress that fell to the Christians in 1129. The castle was of considerable strategic importance as a nearly impregnable defense on the border between Christian and Muslim-ruled territory. The castle was never conquered and was successfully defended against the King of Castile in the 13th century. The completion of the Reconquista at the end of the 15th century ended its military significance. Although it fell into ruin in the following centuries, since 1971 it has progressively been restored by its private owners. It can be visited with permission from the owners. The Castle of Zafra and the surrounding area have a long history of habitation. Pottery fragments from the Bronze and Iron Ages have been found in rock cavities and in the vicinity of the castle. The Romans may have occupied the rock on which the castle now stands, as the remains of structures from the classical era have been found in the castle's grounds. The earliest known fortress on the site is believed to have been established by the Visigoths during the time of the Visigothic Kingdom prior to around 720. The Moors had a fortification there which was used by the Taifa of Toledo.