Athens , Ancient Greek: Ἀθῆναι Athēnai), is the capital and largest city of Greece. Athens dominates the Attica region and is one of the world's oldest cities, with its recorded history spanning around 3,400 years, and the earliest human presence started somewhere between the 11th and 7th millennia BC. Classical Athens was a powerful city-state that emerged in conjunction with the seagoing development of the port of Piraeus. A centre for the arts, learning and philosophy, home of Plato's Academy and Aristotle's Lyceum, it is widely referred to as the cradle of Western civilization and the birthplace of democracy, largely because of its cultural and political impact on the European continent and in particular the Romans. In modern times, Athens is a large cosmopolitan metropolis and central to economic, financial, industrial, maritime, political and cultural life in Greece. In 2015, Athens was ranked the world's 29th richest city by purchasing power and the 67th most expensive in a UBS study.

Athens is recognised as a global city because of its geo-strategic location and its importance in shipping, finance, commerce, media, entertainment, arts, international trade, culture, education and tourism. It is one of the biggest economic centres in southeastern Europe, with a large financial sector, and its port Piraeus is the largest passenger port in Europe, and the second largest in the world. The municipality (City) of Athens had a population of 664,046 (in 2011, 796,442 in 2004) within its administrative limits, and a land area of 39 km2 (15 sq mi). The urban area of Athens (Greater Athens and Greater Piraeus) extends beyond its administrative municipal city limits, with a population of 3,090,508 (in 2011) over an area of 412 km2 (159 sq mi). According to Eurostat in 2004, the Athens Larger Urban Zone (LUZ) was the 7th most populous LUZ in the European Union (the 5th most populous capital city of the EU), with a population of 4,013,368. Athens is also the southernmost capital on the European mainland.

The heritage of the classical era is still evident in the city, represented by ancient monuments and works of art, the most famous of all being the Parthenon, considered a key landmark of early Western civilization. The city also retains Roman and Byzantine monuments, as well as a smaller number of Ottoman monuments.

Athens is home to two UNESCO World Heritage Sites, the Acropolis of Athens and the medieval Daphni Monastery. Landmarks of the modern era, dating back to the establishment of Athens as the capital of the independent Greek state in 1834, include the Hellenic Parliament (19th century) and the Athens Trilogy, consisting of the National Library of Greece, the Athens University and the Academy of Athens. Athens was the host city of the first modern-day Olympic Games in 1896, and 108 years later it welcomed home the 2004 Summer Olympics. Athens is home to the National Archeological Museum, featuring the world's largest collection of ancient Greek antiquities, as well as the new Acropolis Museum.