An underground city is a network of underground tunnels that connect buildings, usually in the downtown area of a city. These may include office blocks, shopping malls, train and metro stations, theatres, and other attractions. An underground city can usually be accessed through the public space of any of the buildings connecting to it, and sometimes has separate entries as well.

Underground cities are especially important in cities with cold climates, as they permit the downtown core to be enjoyed year round without regard to the weather.

Underground cities are similar in nature to skyway systems and may include some buildings linked by skyways or above-ground corridors rather than underground.

Cities with underground cities include:

  • Montreal (la ville souterraine) whose 32 kilometres of tunnels connect seven downtown metro stations and many important office towers and malls, with smaller tunnel systems in other parts of the city linking other attractions to metro stations. Montreal is famous for its underground city and it is often visited by tourists. Map of the underground city (PDF format)

  • Toronto (PATH) linking the most important buildings in much of the downtown core to five TTC subways stations with 27 kilometres of walkways. PATH homepage

  • Atlanta (Underground Atlanta) covering six city blocks, includes retail shopping and restaurants. Begun in 1968, re-opened after a financially-forced closure in 1989. Underground Atlanta homepage

  • Chicago (Pedway) consisting of approximately 4 disjoint tunnel systems, the largest covering about 10 blocks, connecting such buildings and transit stations as Metra's Randolph Street Station, the Chicago Cultural Center, Marshall Field's flagship store at State and Randolph, Chicago Transit Authority's State Street and Dearborn Street subway stations, City Hall, and the State of Illinois (James R Thompson) Center. Pedway Map

  • Helsinki covering central railway station area, two subway stations (Rautatientori, Kaisaniemi) and shopping malls. Also in two other subway stations have undergrounds like this, like Hakaniemi and Sörnäinen.

  • Osaka has enormous underground networks in the Umeda, Namba, and Shinsaibashi districts, which include retail shopping, restaurants, and subway and intercity rail stations.