To the east is the Laconian Gulf, to the west the Messenian Gulf. The peninsula forms a continuation of the Taygetos mountain range, the western spine of the Peloponnese.

The terrain is mountainous and inaccessible. The name "Mani" is thought to have originally meant "dry" or "treeless." Until recent years many Mani villages could be reached only by sea. Today a narrow and winding road extends down the west coast from Kalamata to Areopoli, then south to Akrotainaro (the pointy cape which is the most southward soil of continental Greece and continental Europe) before it turns north until Gytheio.

Mani has been traditionally divided into three regions:

* Exo Mani or Outer Mani to the northwest,
* Kato Mani or Lower Mani to the east,
* Mesa Mani or Inner Mani to the southwest.

A fourth region named Vardounia to the north is also sometimes included.