The first alluvial terrace, at altitude, was fully occupied by the western part of the communal territory in the 1960s. The city of Valence then expanded eastward, on the Riss terrace, at an altitude of approximately . To the south, the Lautagne plateau, at an altitude of , determines a narrow groove between this advance from the terrace of la Léore and the Rhône, which has limited the development of the city in that direction. At the end of the 20th century, the city was again cut off from the Rhône by the construction of the A7 autoroute. Port areas are alone in the south towards Portes-lès-Valence. The Valence agglomeration stretches on the right bank of the Rhône, but is limited by the edge of the Vivarais plateau. However, it includes the communes of Guilherand-Granges, Saint-Péray, Cornas and Soyons.