was badly affected by the Second World War and Greek Civil War, experiencing some of the worst atrocities committed in Greece during those conflicts. Living standards improved dramatically throughout Greece after the country accedes to the European Union in 1981. The Corinth Canal was completed in the late 19th century, linking the Aegean Sea with the Gulf of Corinth and the Ionian. In 2001, the Rio-Antirio Bridge was completed, linking the western Peloponnese to western Greece. In late August 2007, large parts of Peloponnese suffered from wildfires, which caused severe damage in villages and forests and the death of 77 people. The impact of the fires to the environment and economy of the region are still unknown. It is thought to be one of the largest environmental disasters in modern Greek history. Regional units Arcadia – 100,611 inhabitants Argolis – 108, 636 inhabitants Corinthia – 144,527 inhabitants (except municipalities of Agioi Theodoroi and most of Loutraki-Perachora, which lie east of the Corinth Canal) Laconia – 100,871 inhabitants Messenia – 180,264 inhabitants Achaea – 331,316 inhabitants Elis – 198,763 inhabitants Islands (only the municipality Troizinia and part of Poros) Cities The principal modern cities of the Peloponnese are (2011 census): Patras – 170,896 inhabitants Kalamata – 62,409 inhabitants Corinth – 38,132 inhabitants Tripoli – 30,912 inhabitants Aigio – 26,523 inhabitants Pyrgos – 25,180 inhabitants Argos – 24,700 inhabitants Sparta – 19,854 inhabitants Nafplio – 18,910 inhabitants Amaliada - 18,303 inhabitants Archaeological sites The Peloponnese possesses many important archaeological sites dating from the Bronze Age through to the Middle Ages. Among the most notable are: Bassae (ancient town and the temple of Epikourios Apollo and Greece's first UNESCO World Heritage Site) Corinth (ancient city) Epidaurus (ancient religious and healing centre and UNESCO World Heritage Site) Koroni (medieval seaside fortress and city walls) Kalamata Acropolis (medieval acropolis and fortress located within the modern city) Messene (ancient city) Methoni (medieval seaside fortress and city walls) Mystras (medieval Byzantine fortress-town near Sparta and UNESCO World Heritage Site) Monemvasia (medieval Byzantine fortress-town) Mycenae (fortress-town of the eponymous civilization and UNESCO World Heritage Site) Olympia (site of the Ancient Olympic Games and UNESCO World Heritage Site) Sparta Pylos (the Palace of Nestor and a well-preserved medieval/early modern fortress) Pavlopetri (the oldest underwater city in the world, located in Vatika Bay, dating from the early Bronze Age 3,500 BCE) Tegea (ancient religious centre) Tiryns (ancient fortified settlement and