Castilfrío de la Sierra

• Official Name — Castilfrío de la Sierra • Type — Municipality • Subdivision Type — Country • Subdivision Type1 — Autonomous community • Subdivision Name1 — Castile and León • Subdivision Type2 — Province • Subdivision Name2 — Province of Soria • Subdivision Type3 — Municipality • Subdivision Name3 — Castilfrío de la Sierra • Area Total Km2 — 12 • Population Density Km2 — auto • Time Zone — CET • Utc Offset — +1 • Time Zone Dst — CEST • Utc Offset Dst — +2

During the Middle Ages, the locality belonged to the Community of Villa y Tierra de Soria as part of the Sexmo de Tera. The 1528 Census of Pecheros (taxpaying households), which excluded clergy, nobility, and hidalgos, documented 26 pecheros—families subject to taxation. In the original document, the village is listed as Castelfrío de San Juan. Following the collapse of the Old Regime, the locality became a constitutional municipality, then known as Castil Frío, in the region of Old Castile, Partido de Soria. By the 1842 census, it had 85 households and 348 residents. By the mid-19th century, the village comprised approximately 100 houses. The settlement is described in the sixth volume of Pascual Madoz’s Diccionario geográfico-estadístico-histórico de España y sus posesiones de Ultramar as follows: