Mount Aiona is composed of dark peridotitic rocks that rises on the main watershed of the Ligurian Apennines; it is one of the most beautiful and characteristic peaks of the entire mountain range and it represents the highest point of the Apennine watershed between Colle di Cadibona and Passo della Cisa.

The summit area is represented by a gigantic detrital plateau on which only meager grasses grow. Approximately in the center of the plateau is the highest point of the mountain, indicated by a large metal cross and a pyramid of stones.

The second important elevation is the north peak (1692 m), which overlooks the Val d'Aveto dominating vast beech forests, and which branches out towards the north with a steep and aerial rocky ridge. Seen from the valley below of the Gramizza Torrent, a tributary of the Aveto, the northern peak appears like an elegant rocky pyramid. Its slopes are very steep, made up of walls of broken rocks and vast screes. On the sides of the northern peak there are three cirque-shaped escarpments, of glacial origin. From the largest cirque, located on the north-west side, the Rezzoaglio Torrent originates, which in its initial stretch has dug a deep rocky gorge, known among hikers as the "Aiona Canyon".

The northern ridge of the mountain, however, quickly lowers to the Cerighetto Pass, and then rises again into the wooded dome of Monte Cerighetto (1528 m), a small basaltic peak that offers a beautiful view of the Aiona glacial cirques. The third elevation of the summit plateau is the south peak (1688 m), surmounted by a statuette of the Madonna. The southern peak overlooks the "maritime" Val Penna, tributary of the Sturla torrent, lowering 1200 meters towards the valley floor, among steep meadows dotted with boulders, beech woods, chestnut trees and, now almost at the bottom, terraced strips and cultivated fields.

The geology of ​​Mount Aiona is composed by ultramafic masses, generally in the form of serpentinites and tectonitic peridotites, associated with breccias of different nature and small granitic flaps, which can be classified in the Aiona Subunit. In the sector of the Penna and Cantomoro mountains, pillow basalts emerge, locally massive basalts, in the form of olistoliths of multi-decametric dimensions, associated with basaltic breccias and, sometimes, cataclased and altered granites. The peridotitic outcrop that can be seen at the foot of Mount Aiona, just before arriving at the vast Prato Mollo plateau, is also particular in its shape and characteristics: the famous Pietra Borghese. This rock mass, whose original core belonged to the subcontinental mantle, has an age estimated at more than 2 billion years, and represents one of the oldest rocks in Italy.