In geography, a cape is a headland, peninsula or promontory extending into a body of water, usually a sea. A cape usually represents a marked change in trend of the coastline, often making them important landmarks in sea navigation. This also makes them prone to natural forms of erosion, mainly tidal actions, resulting in a relatively short geological lifespan. Capes can be formed by glaciers, volcanoes, and changes in sea level. Erosion plays a large role in each of these methods of formation.
Capes (and other headlands) are conspicuous visual landmarks along a coast, and sailors have relied on them for navigation since antiquity. The Greeks and Romans considered some to be sacred capes and erected temples to the sea god nearby.
Greek peripli describe capes and other headlands a sailor will encounter along a route. The Periplus of Pseudo-Scylax, for instance, illustrates a clockwise journey around Sicily using three capes that define its triangular shape: Cape Peloro in the northeast, Cape Pachynus in the southeast, and Cape Lilybaeum in the west. Sicily itself was referred to as Trinacria (or Three Capes) in antiquity.
Homer's works reference a number of capes to describe journeys around the Mediterranean Sea. Menelaus, Agamemnon, and Odysseus each faced peril at the notoriously dangerous Cape Malea at the southeastern tip of the Peloponnese. Menelaus navigated via Cape Sounion on his way home from Troy, and Nestor stopped at Cape Geraestus (now Cape Mandelo) on Euboea to give offerings at the altar to Poseidon there.
Cape Gelidonya (then known as Chelidonia) on the coast of Turkey served as a bearing aid for ships heading to the Egyptian port of Canopus, directly to the south. Cape Sidero on the eastern tip of Crete was a waypoint for Jason and the Argonauts returning from Libya as well as for Paul the Apostle as he traveled from Caesarea to Rome.
The three great capes (Africa's Cape of Good Hope, Australia's Cape Leeuwin, and South America's Cape Horn) defined the traditional clipper route between Europe and the Far East, Australia and New Zealand. They continue to be important landmarks in ocean yacht racing.