The sea borders Italy as far as its border with France, and the French island of Corsica. In the east the sea borders the Tyrrhenian Sea, while in the west it borders the Mediterranean Sea proper. Genoa is the most prominent city in the area. The northwest coast is noted for its scenic beauty and favourable climate.
The Gulf of Genoa is its northernmost part. The sea receives the Arno River from the east and many other rivers that originate in the Apennines. The ports of Genoa, La Spezia, and Livorno are on its rocky coast. It reaches a maximum depth of more than 9,300 feet (2,850 m) northwest of Corsica.
The International Hydrographic Organization defines the limits of the Ligurian Sea as follows:
On the Southwest. A line joining Cape Corse (Cape Grosso, 9°23'E) the Northern point of Corsica to the frontier between France and Italy (7°31'E).
On the Southeast. A line joining Cape Corse with Tinetto Island (44°01′N 9°51′E / 44.017°N 9.850°E / 44.017; 9.850) and thence through Tino and Palmaria Islands to San Pietro Point (44°03′N 9°50′E / 44.050°N 9.833°E / 44.050; 9.833) on the Coast of Italy.
On the North The Ligurian Coast of Italy.
In order to provide protection for the numerous cetacean (whales and dolphins; porpoises are not found in this part of the Mediterranean Sea) species in the Ligurian Sea the bordering countries established the sea as a SPAMI in 1999. The International Ligurian Sea Cetacean Sanctuary now covers 84,000 km² covering territorial waters as well as high sea.