The village lies in the shadow of the Mount San Petrone, in the area of Ampugnani. The name of A Porta goes back to times were roads didn't exist on the island: A Porta (to translate «The Door») was the crossroads of mule footpaths linking Bastia and the coastline to the «Granary of Corsica» chestnut groves of Castagniccia. The built heritage is rich and typical of the area, and count several «Palazzi» old manor houses. Nowadays, A Porta is very lively and we can find numerous shops, services and local producers.

To discover
- The Baroque church of San Ghjuvanbattista, built in 1648 and listed as historical monument, and its famous 45m-tower-bell crowned by an hexagonal dome. It contains several classified works of art and an organ from 1780.
- The chapel of Cunfraternita di San Sebastianu è San Roccu, built in 1450 and rebuilt on the endly-19^th century.
- Five lion-headed fountains.
- The vintage cars rallye «Montée Historique de Castagniccia», starting from the village every year in September.