Osma Castle sits on a hill near the Soria town of El Burgo de Osma - Ciudad de Osma, between the Ucero and Abión rivers.
The enclave has its origins in the Celtiberian city of Uxama-Argelae, which passed into Roman hands in the 2nd century. Conquered by the Arabs, it was abandoned in the late Middle Ages, the population moving to the current Osma and building the castle on the hill between the 10th and 11th centuries.
The fortress had three walled enclosures, irregular in shape, since the outline adapted to the relief of the hill on which it sits. It had two towers in the inner enclosure and one tower in the outer enclosure. Between 2016 and 2020 the remains were consolidated and restored, adding walkways and informative signage at different key points.