Castellfollit de la Roca is a town in an area of less than a square kilometre, making it one of the smallest towns in Catalonia. The basalt cliff where the town is located, over 50 metres high, was produced by two lava flows from the volcanic eruptions which took place in the past. The first took place 217,000 years ago. It came from the volcano of Batet and flowed along the valley of Fluvià. The second one, a more recent formation from the volcanoes of Begudà, is 192,000 years old and has formed into prismatic shapes coming from the river Turonell. The erosive action of the rivers ended up cutting the cooled lava turned into basalt until leaving it as we know it today. Castellfollit de la Roca has been an important crossing point between La Garrotxa and Empordà since Roman times, although it was in the Middle Ages when the village, formed by squares and dark, narrow streets, acquired its medieval structure. On one side of the cliff stands the old church of Sant Salvador with its bell tower, nowadays used as a cultural centre.