The island is, unlike the nearby Ischia and Procida, of karst origin. Initially it was joined to the Sorrento Peninsula, except that it was later submerged in part by the sea and then separated from the mainland, where today is the Strait of Bocca Piccola. Capri has a complex morphological structure, with peaks of medium height (Monte Solaro 589 m and Monte Tiberio 334 m) and vast internal plateaus, among which the main one is called "Anacapri".
The coast is jagged with numerous caves and coves that alternate with steep cliffs. The caves, hidden under the cliffs, were used in Roman times as nymphs of the sumptuous villas that were built here during the Empire. The most famous is undoubtedly the Blue Grotto, where magical light effects were described by many writers and poets.
Characteristic of Capri are the famous Faraglioni, three small rocky islets a short distance from the shore that create a scenic and landscape effect; they were also given names to distinguish them: Stella for the one attached to the mainland, Faraglione di Mezzo for the one interposed to the other two and Faraglione di Fuori (or Scopolo) for the one furthest from the island .
The island preserves numerous animal and plant species, some endemic and very rare, like the blue lizard, which lives on one of the three Faraglioni. The vegetation is typically Mediterranean, with prevalence of agaves, prickly pears and brooms. In Capri there are no more sources of drinking water and the water supply is guaranteed by submarine pipelines coming from the Sorrento peninsula. Electricity is supplied by a private company on site.
The main inhabited areas of the island are Capri, Anacapri, Marina Grande, while the other marine side of Capri, Marina Piccola, is less inhabited and even more subject to the phenomenon of speculation that has hit the whole island since the early eighties to today.