Madrid-Barajas Airport (airport code MAD) is an international bridge connecting Europe and Central and South America. Madrid has four terminals with Terminals 1, 2 and 3 serving Spanish carriers and members of Star Alliance and Skyteam while Terminal 4 services Iberia Airlines and international carriers. Only 15 kilometers from the city center, passengers can get to Madrid by taking Metro Line 8 (pink on the metro map), which departs from Terminals 2 and 4. The airport is operated by Aena Aeropuertos, which also operates 47 other airports in Spain. A mixture of ancient and modern, Madrid is half bustling metropolis of six million people with modern skyscrapers and half quintessential village with narrow streets and sidewalk cafes. To show off the city's culture, Madrid Airport also houses permanent and revolving collections of artwork. Continuing their environmental commitments, Madrid-Barajas Airport constantly reviews sustainability practices and has had ISO certification since 2000.