What are the mountain ranges of italy and what benefits did they provide the ancient romans?

The mountain ranges of Italy are the Apennine ranges/mountains which are surrounded by coastlands that are not wide, but covered by green flourishing vegetation. The Apennine mountains greatly benefitted the ancient Romans and Rome because they served as a natural fortress/form of protection against foreign attacks, armies and invasion, and reduced a lot threats often created from the other side of the ranges.