
Lisbon is the capital and the largest city of Portugal, with an estimated population of 544,851 within its administrative limits in an area of 100.05 km2. Lisbon's urban area extends beyond the city's administrative limits with a population of around 2.7 million people, being the 11th-most populous urban area in the European Union. Lisbon is recognised as an alpha-level global city because of its importance in finance, commerce, media, entertainment, arts, international trade, education and tourism. Lisbon is one of two Portuguese cities (alongside Porto) to be recognised as a global city. The motorway network and the high-speed rail system of Alfa Pendular links the main cities of Portugal to Lisbon. The city is the 9th-most-visited city in Southern Europe, after Istanbul, Rome, Barcelona, Milan, Athens, Venice, Madrid and Florence with 3,539,400 tourists in 2018. Lisbon is one of the oldest cities in the world, and the second-oldest European capital city (after Athens), predating other modern European capitals by centuries. Lisbon's name may have been derived from Proto-Celtic or Celtic Olisippo, Lissoppo, or a similar name which other visiting peoples like the ancient Phoenicians, Greeks and Romans adapted accordingly, such as the pre-Roman appellation for the Tagus River, Lisso or Lucio. Classical authors writing in Latin and Greek, including Strabo, Solinus, and Martianus Capella, referred to popular legends that the city of Lisbon was founded by the mythical hero Ulysses (Odysseus).