The Peloponnese is a peninsula that constitutes the southernmost part of mainland Greece. While technically it may be considered an island since the construction of the Corinth Canal in 1893, like other peninsulas that have been separated from their mainland by man-made bodies of waters, it is rarely, if ever, referred to as an "island". It has two land connections with the rest of Greece, a natural one at the Isthmus of Corinth, and an artificial one by the Rio-Antirio bridge. The peninsula has a mountainous interior and deeply indented coasts. It possesses four south-pointing peninsulas, the Messenian, the Mani, the Cape Malea and the Argolid in the far northeast of the Peloponnese.Two groups of islands lie off the Peloponnesian coast: the Argo-Saronic Islands to the east, and the Ionian to the west. The island of Kythera, off the Epidaurus Limera peninsula to the south of the Peloponnese, is considered to be part of the Ionian Islands.