The Athens Metro (3 lines, €1.20 single / €4.10 for a 24-hour pass) is clean, air-conditioned, and connects the airport to the city centre in under an hour. Most major sites are walkable from Monastiraki, Thissio, or Akropoli stations. Avoid renting a car in the city — traffic is heavy and parking is scarce. The express bus X95 runs 24 hours between Athens International Airport (Eleftherios Venizelos) and Syntagma Square for €6.20. A taxi from the airport to the centre costs a flat €40 (€55 midnight–5 AM) and takes 35–50 minutes. The metro (Line 3) also serves the airport and deposits you at Monastiraki or Syntagma.