Arco Naturale, Capri, Italy. Giorgio Sommer (1880). Public Domain.
The island Capri, drawn by a 19th century artist. Public Domain.

Capri is an island at the southern end of the Bay of Naples. It is located off the tip of the Sorrento Peninsula, in the Tyrrhenian Sea. There are two towns on the island, Capri and Anacapri. The ferry from Naples lands at the harbour Marina Grande, which also almost a village. However, there are houses all over the island, on any slope and even on some cliffs or sea stacks. Some cane only be reached on very strange roads or by foot. And thats actually the case since Roman times, when numerous rich Romans built villas on the island. This has not changed until today, modern day high society with villas include the German steel baron Krupp or the Italian writer, film-maker, war correspondent and diplomat Curzio Malaparte.

The island is continually lifted and lowered by the changes in volcanic activity in the area. It consists of a massive basement of Jurassic and Cretaceous limestones covered by much younger conglomerates and sandstone and Pleistocene pyroclastic deposits. The coast is mostly very steep, several hundred meter high cliffs of Jurassic limestone. The limestone is karstified, but due to the rather fast up and down movement the caves are rather strange. And there are numerous sea caves, also due to the movements sometimes high above the sea level or even below the sea level. The most impressive example is obviously the Grotta Azzurra which could easily be visited during Roman times and contained a Roman temple. Today it is half filled by sea water and the sun shining into the now submerged entrance is filtered by the sea water and produced the namesake blue colour.