The southeastern border of the Ligurian Apennines is the Fiume Magra, which projects into the Tyrrhenian Sea south of La Spezia, and the Fiume Taro, which runs in the opposite direction to join the Po. The divide between the two upper river valleys is the Cisa Pass. Under it (in two tunnels) runs the Autostrada della Cisa between Spezia and Parma.