Greece, officially the Hellenic Republic and known since ancient times as Hellas, is a country in Southern Europe. According to the 2011 census, Greece's population is around 11 million. Athens is the nation's capital and largest city.Greece is strategically located at the crossroads of Europe, Western Asia, and Africa, and shares land borders with Albania to the northwest, the Republic of Macedonia and Bulgaria to the north and Turkey to the northeast. The country consists of nine geographic regions: Macedonia, Central Greece, the Peloponnese, Thessaly, Epirus, the Aegean Islands, Thrace, Crete, and the Ionian Islands. The Aegean Sea lies to the east of the mainland, the Ionian Sea to the west, and the Mediterranean Sea to the south. Greece has the longest coastline on the Mediterranean Basin and the 11th longest coastline in the world at 13,676 km in length, featuring a vast number of islands. Eighty percent of Greece consists of mountains, of which Mount Olympus is the highest, at 2,917 m.Modern Greece traces its roots to the civilization of Ancient Greece, which began with the Aegean Civilizations of the Bronze Age. Considered the cradle of all Western civilization, Greece is the birthplace of democracy, Western philosophy, the Olympic Games, Western literature and historiography, political science, major scientific and mathematical principles, and Western drama, including both tragedy and comedy. The cultural and technological achievements of Greece greatly influenced the world, with many aspects of Greek civilization being imparted to the East through Alexander the Great's campaigns, and to the West through its incorporation into the Roman Empire. This rich legacy is partly reflected by the 18 UNESCO World Heritage Sites located in Greece, ranking it 6th in Europe and 13th in the world. The modern Greek state, which comprises most of the historical core of Greek civilization, was established in 1830 following the war of independence from the Ottoman Empire.Greece is a democratic, developed country with an advanced high-income economy, a high standard of living and a very high Human Development Index. Greece is a founding member of the United Nations, a member of what is now the European Union since 1981, and is also a member of numerous other international institutions, including the Council of Europe, NATO, OECD, OSCE and the WTO. Greece's economy is also the largest in the Balkans, where Greece is an important regional investor.