Frías has a total area of 32 square kilometers and a population of 284 inhabitants, 155 men and 129 women (INE 2007), including its respective neighborhoods of Tobera and Quintana-seca. The city of Frías, in addition to standing out as the smallest in Spain, immerses visitors in an exquisite medieval atmosphere that owes its origins to Alfonso VIII, who built it on the rock at the beginning of the 12th century in order to protect and repopulate this border of Old Castile. This strategy brought numerous privileges to the city’s inhabitants, in addition to the imposing fortress comprising the castle, the church of San Vicente, the bridge, and the wall, which facilitated the defense of their interests and progressively boosted their economy, to the point of supplying the needs of the more than 6,000 inhabitants at the beginning of the 16th century.