Urban exploration is a term that been used for activities like urban rock climbing, urban spelunking, building hacking or urban caving. It is also used with reference to draining while exploring drains.

This activity poses as a risky task in terms of physical as well as legal complications. There are several associated activities with urban exploration that violate laws regionally and locally, sometimes going against anti-terrorism regulations, and even considered as trespassing and privacy invasion.

Targets of exploration

The exploration targets can be of various types depending on the country. From amusement parks, factories, fallout shelters, schools, sanatoriums, to places like power plants, hospitals, missile silos, asylums, rugged houses, etc.

The term haikyo (meaning ‘abandoned place’) is commonly used in Japan in reference to ruins during urban exploration. Haikyo is common in Japan now because of the rapid industrialization, for example at Hashima Island, the damages of World War II, the bubble of real estate of 1980s and the tsunami and earthquake at Tōhoku in 2011.

Active buildings

Urban explorations also depict the practice of exploring buildings which are in use or active, this includes gain of access to safely secured or restricted or ‘member-only’ places, elevator rooms, roofs, mechanical rooms and other places that are normally unseen in building.


Catacombs have been discovered around the globe at places like, Naples, Paris, Odessa and Rome and have been extensively explored. In Paris, the Mines have been discovered to comprise of underground tunnels, now restricted from public view just like catacombs, and have been named ‘Holy Grail’ because of their historic nature. The individuals who explore these are referred to as cataphiles.

Sewers and storm drains

Draining, i.e. entering storm drains is an activity that comes under urban exploration. This activity has grown in popularity to an extent that there are now groups especially dedicated to draining, the Cave Clan from Australia for instance. Draining follows many presets and guidelines, the most important one being ‘If it rains then no drains!’ A rainfall increases the hazards of getting trapped or washed away, and even getting killed. There is a subset of urban explorers who explore sewers and are at times the only way to access caves and similar subterranean features. While it is well known that sewers are a symbol of danger owing to the high level of risk of getting poisoned by the build-up of harmful and toxic gases, mainly hydrogen sulphide and methane, explorations still go on with numerous fatal accidents happening time and again around the globe with fortunate people who manage to overcome the toxic gases.

Utility tunnels

There are utility tunnels in Zurich, Switzerland’s Universalities and also other places like hospitals wherein harmful steams of high temperature are distributed from a common heating plant to buildings for heating and cooling purposes. The pipes used for this are generally built through utility tunnels and are built in a way to be accessed only for maintenance works.

At some steam tunnels the floors are dirty, with poor lighting conditions and also where the temperatures are never below 45oC or 113oF, while some of these tunnels have floors of concrete and with bright light conditions and moderate temperatures. Most of the steam tunnels possess airborne asbestos and also have intake fans of large sizes that bring in fresh air and push out the hot air. However, breathing protection is often required while entering them to avoid respiratory complications.

Urban exploration has gained an increased popularity which is now evident through high media attention. For example, shows like Urban Explorers on Discovery Channel. Ghost Hunting of the Atlantic Paranormal Society, MTV’s Fear, etc, have a great number of audiences. The movie After... of 2006 is a thriller film that is set in the underground subways of Moscow. It depicts urban explores that are stuck under extreme conditions. The 5th and 6th editions of Hackers on Planet Earth Conference, also have displayed urban exploration with numerous media content complementing the activity. Cities of the Underworld, started in 2007, is another contributing series that successfully completed three seasons on air History Channel.