The octagonal building of Can Ferrerons Historical milestone · Premià de Mar, Maresme, Barcelona Image of Premià de Mar, not of the place itself. Beneath the urban centre a Roman construction of octagonal plan raised around the fourth century is preserved, linked to a villa devoted to wine. It is an uncommon plan in Hispania and today it is displayed as a museum and integrated into a modern building. siglo IV Photo: Deosringas (CC BY-SA 3.0) What to see and do in Premià de Mar