Greenwich Foot Tunnel, interior, Greenwich, London, England, United Kingdom, Europe

People in an underground walkway, Beijing, China

Stairs in tunnel under houses, Pitigliano, Province Grosseto, southern Tuscany, Italy, Europe

Dark tunnel

Graffiti in an underpass in Leoben, Styria, Austria, Europe

Man approaching a group of menacing-looking youths in a dark pedestrian underpass

Illuminated pedestrian tunnel, walkway in the underground city of Montreal, Quebec, Canada, North America

Modern pedestrian underpass with surveillance cameras

Group of youths passing through a dark underpass

Man carrying a shopping bag in a pedestrian underpass

Pedestrian subway, Stuttgart, Baden-Wuerttemberg, Germany, Europe