At the start of the 19th century, the only access road between Fréjus and Mandelieu was the Route de la Poste, an old Roman way that crossed the Estérel and Tanneron massifs via the Adrets. The city of Saint-Raphaël was created with the arrival of the railway around 1880-1890 when the Paris-Lyon-Méditerranée railway company undertook the completion of its line towards Nice. The difficulty of crossing the Estérel was made worse by the location of the new Saint-Raphaël station, too far removed from a route that would follow the Route de la Poste. The choice was then directed towards bypassing the massif more or less along the coast, which required the construction of engineering structures such as the Anthéor viaduct or the following tunnel.