Greece, officially the Hellenic Republic, known also as Hellas, is a country located in Southeast Europe. Its population is approximately 10.7 million as of 2018; Athens, the nation's capital, is its largest city, followed by Thessaloniki. Situated on the southern tip of the Balkan Peninsula, Greece is located at the crossroads of Europe, Asia, and Africa. It shares land borders with Albania to the northwest, North Macedonia and Bulgaria to the north, and Turkey to the northeast. The Aegean Sea lies to the east of the mainland, the Ionian Sea to the west, the Cretan Sea and the Mediterranean Sea to the south. Greece has the longest coastline on the Mediterranean Basin featuring many islands, of which 227 are inhabited. Eighty percent of Greece is mountainous, with Mount Olympus being the highest peak at 2,918 metres (9,573 ft). Greece is considered the cradle of Western civilisation. Greece emerged as a modern nation state in 1830 following a war of independence. Greece is a unitary parliamentary republic and developed country with an advanced high-income economy.