© Istockphoto| Napoli, stazione Toledo 

© Istockphoto| Napoli, stazione Università

© Istockphoto| Stoccolma, stazione T- Centralen

© Istockphoto| Stoccolma, stazione Kungstradgarden 

© Istockphoto| Stoccolma, stazione Solna 

© Istockphoto| Parigi, Arts et métiers

© Istockphoto| Monaco di Baviera, Westfriedhof

© Istockphoto| Lisbona, Olaias 

© Istockphoto| Mosca, Komsomolskaya

© Istockphoto| Mosca, Okskaja  

© Istockphoto| San Pietroburgo, Avtovo 

© Istockphoto| Tashkent, Kosmonavtlar (Uzbekistan)

© Istockphoto| Taiwan, Formosa Boulevard

© Istockphoto| Dubai : una stazione metropolitana abbarbicata alle superstrade urbane

© Istockphoto| Shanghai, Bund Sightseeing Tunnel

© Istockphoto| Washington DC, Metro Center