Peloponnesus is a peninsula in southern Greece. It is also known as Peloponnese or Peloponnesos, and is written in Greek as Πελοπόννησος. It covers 21,549 sq km (8,320 sq mi). It was connected to mainland Greece by the Isthmus of Corinth until 1893, when the construction of the Corinth Canal severed the link, effectively turning Peloponnesus from a peninsula into an island. However, Peloponnesus is rarely referred to as an island.
Ruins of the ancient theater of Sparta Source: https://commons.wikimedia.org/wiki/File:Ancient_sparta_theater.jpg Author: Nickthegreek82
Presently Peloponnesus is connected to the Greek mainland by the Rio-Antirio Bridge. It is divided among three regions, or peripheries, of modern Greece. The main part is occupied by the Peloponnese Periphery, while the western third is occupied by Western Greece Periphery and a small area on the eastern tip by Attica Periphery.
Acrocorinth, the acropolis of Ancient Corinth Source: https://commons.wikimedia.org/wiki/File:%CE%91%CE%BA%CF%81%CE%BF%CE%BA%CF%8C%CF%81%CE%B9%CE%BD%CE%B8%CE%BF1.jpg Author: aikijuanma
Southern foothills of the Taygetus range at Mani Peninsula, Peloponnesus Source: https://commons.wikimedia.org/wiki/File:Mani_Clouds.jpg Author: AlMare