Castle of Oló Monument · Santa Maria d'Oló, Moianès, Barcelona Image of Santa Maria d'Oló, not of the place itself. Oló castle is a medieval fortification located at the top of the old village of Santa Maria d'Oló (Moianès, Barcelona), at the southern end of where the town extends today. It was responsible for the defence of the whole territory of Santa Maria d'Oló and that of Estany. The name Oló has been documented since the year 889 and the castle is explicitly mentioned in 931; its lordship was comital, exercised first by viscounts' deputies and later by the Oló family, descended from the viscounts of Girona. After passing to the Montcada family, it was sold in 1364 to the monastery of Santa Maria de l'Estany, which provoked a popular revolt and years of litigation and sieges until the monks conquered it. It later belonged to the Five Royal Dignities, until it was reincorporated into the Crown in 1606. The castle was enlarged in the 18th century. Photo: José Luis Mieza (CC BY 2.0) What to see and do in Santa Maria d'Oló