Why go
The Écusson makes more sense when you know its edges. Follow the smaller streets inside the boulevard ring, then find the Tour de la Babotte and Tour des Pins as surviving markers of the wall. The Porte du Peyrou opens a different, later approach to the old town.
The full story
The name Écusson refers to the shield-like shape of Montpellier's historic centre. Its dense street pattern has remained central to the city since the medieval period. Boulevards now follow much of the line of former fortifications, so the boundary of the old town can still be read on a map and underfoot. The Tour de la Babotte and Tour des Pins are the two notable surviving towers of that enclosure. The Babotte later served as an astronomical observatory; the Tour des Pins had several uses over the centuries. After the siege of 1622, parts of the walls were dismantled. Later gateways and formal spaces changed the old town's entrances. The Porte du Peyrou, built on the former defensive line, opens toward a promenade rather than functioning as a medieval gate. Moving from the narrow inner lanes through that arch makes the successive street plans especially clear.