Milestone A Roman milestone engraved in the name of the Emperor Constantine. This milestone stands against the chancel of the parish church and indicates the distance to the centre of Rome. Opening hours Freely available Suggestions Town hall Headquarters for the local council and the district court. The Old Town Martigny -Bourg is the oldest inhabited part of the town. Semblanet's Mill This historic mill is still working. A single waterwheel activates about one hundred different mechanisms.