Chaîne de l'Estaque

1927. Starting near the village of Le Rove, it cuts through the Chaîne de l'Estaque at sea level. It is considered one of the greatest pieces of engineering

a sea level passage through the 278 m (912 ft) maximum altitude Chaîne de l'Estaque [fr]. The tunnel is 7,120 m (23,360 ft) long, 22 m (72 ft) wide and

Provence". The possibility of building a canal with a tunnel through the chaîne de l'Estaque to the northwest of Marseille had been discussed for many years.