Barons of Erill Historical milestone · la Vall de Boí, Alta Ribagorça, Lleida Lords of the valley since the eleventh century, the Erill promoted the building and decoration of the Romanesque churches of the Boí and held ecclesiastical offices of weight: Berenguer d'Erill introduced the Cistercian rule at the monastery of Lavaix in 1223. siglo XI-XIII Photo: Gustau Erill i Pinyot (CC BY-SA 3.0) What to see and do in la Vall de Boí