Construction work for the tramway led to the discovery of the Gallo-Roman fortifications of Gratianapolis, as well as the remains of a major early Christian edifice. White stones indicate the outline. Rising above the rooftops, Clérieux Tower was part of the ancient Gallo-Roman ramparts, raised in the Middle Ages and the 19C. In the south, the Fountain of the Three Orders commemorates Grenoble's Pre-Revolutionary events in 1788.