Cloaca, Capri

The Cloaca is a Roman-era sewage system on the island of Capri, Italy. The surviving outlet is visible west of Marina Grande [1]. It drained much of the island's northern side, evidenced by numerous smaller tributary drains that fed into the main channel [2]. The sewer's gradient has reversed since antiquity—originally sloping gently south to north, it now dips steeply north to south at approximately 25° [3]. This inversion has been cited as evidence of significant land-level change on Capri since Roman times [4].