Castellterçol

The earliest written record of Castellterçol dates to 898, when a land-sale document stored at the Montserrat Archive refers to the territory of a castle belonging to someone named Terçol, within the region of Osona. The land was already divided among several owners, though sparsely populated and partly uncultivated. From that name — the castle of Terçol — the town's modern name gradually evolved.

By the early eighteenth century, Castellterçol held the title of vila, granted by Philip V, which brought privileges including the right to hold a market. In February 1714, during the War of Spanish Succession, the Catalan army under Antoni Desvalls, Marquis of Poal, quartered here while Bourbon forces under the Count of Montemar were stationed nearby in Moià. The two sides fought a series of skirmishes across the Moianès area. When Bourbon troops moved on Castellterçol, further fighting broke out before they withdrew. A farmhouse called El Criac, on the road to Granera, was burned during these clashes.

A mid-nineteenth-century account describes a town of 350 houses spread unevenly across a hilltop, exposed to strong north and south winds, with one of the coldest but healthiest climates in Catalonia. Its main ailment was asthma. The town had a school of around 30 pupils, a good fountain, several wells, two cotton-weaving factories and two spinning mills. The population then stood at around 1,757.

By 1910, the town had shrunk to 308 houses and roughly 1,384 residents. It served as the seat of an electoral district and had a small detachment of the Mossos d'Esquadra. From 1617 to 1855, the rectors of the parish church held the title of paborde, appointed by the monastery of Santa Maria de l'Estany, which held possession of the parish throughout that period.

The town has a castle and a series of roadside oratories, Els Oratoris. The Casa-Museu Prat de la Riba, dedicated to the Catalan political figure, is managed by the Museum of History of Catalonia. On the outskirts, there are one or more ice wells, pous de glaç, used historically for storing ice.

In the town centre, the Espai Franc functions as an exhibition space, and the Centre Espai Escènic hosts performing arts.