Montferrer i Castellbò Main Festival Activity · Montferrer i Castellbò, Alt Urgell, Lleida Image of Montferrer i Castellbò, not of the place itself. The Festa Major of Montferrer i Castellbò is celebrated in the former viscounty of Castellbò, a focus of Cathar sympathies in the 13th century, whose viscount Arnau and his daughter Ermessenda were accused of heresy; Ermessenda's marriage to Roger Bernat II de Foix in 1208 brought the rights over Andorra to the House of Foix. In Montferrer, the municipality's main settlement, built on a hill beside the river Segre, the Festa Major is held on the second-to-last Sunday of August and lasts three days, Saturday, Sunday and Monday. The municipality also celebrates the Festa Vella on the fourth Sunday of September, the feast of Sant Vicenç on 22 January when it falls on a working day, and that of Sant Josep on 19 March, with mass and, sometimes, festive events. Photo: Viquipèdia (CC BY-SA 2.0) What to see and do in Montferrer i Castellbò