城市探险

废墟可能是最热门的城市探险地点。很多废墟最开始由本地人进入，并且可能有涂鸦或其他形式的破坏公物，而另一些则保存得更好。尽管各国各地的可供探索的地点各不相同，但游乐园、谷物升降机、工厂、发电厂、导弹发射井、防空洞、医院、收容所、监狱、学校、贫民房和疗养院等地区通常会备受瞩目。

在日本，废弃的基础设施通常被称为haikyo（意为“废墟”），和城市探索是同义词。[3] haikyo在日本非常常见，这可能由日本过于快速的工业化、二战时的破坏、80年代的房地产泡沫以及2011年东日本大地震和海啸造成。[4]

泽尔贾瓦的地下军用机场

在波斯尼亚和黑塞哥维亚坐落着泽尔贾瓦空军基地（Željava Air Base），一个大型的地下设施。它与1992年被废弃。它位于普列塞维察山（Plješevica mountain）下，靠近比哈奇市（Bihać）。它曾是南斯拉夫最大的地下机场，南斯拉夫的空军基地，欧洲最大的空军基地之一。它有着总长3.5千米的隧道和一些大型设备。现如今，它已成为热门的城市探索景点。然而，1990年波斯尼亚战争所遗留的地雷仍可能存在于此处。[5][6][7]

很多废墟探索者发现了无人居住建筑的破损的美感，有些探索者也是记录所见所闻的自由摄影师，例如那些记述USSR的基础设施的人。[8]

法国一个石灰岩采石场内的

另一种城市探险是探索仍在使用的建筑，包括“闲人勿进”区域，机械室，建筑的屋顶，电梯机房，楼房中长久未被使用的楼层等建筑2中不为知的部分。 "infiltration"（意为渗透）一词通常与探索仍在使用的建筑有关。某些场所禁止外人进入，蓄意进入的探险者可能会侵权。

Catacombs (France)

Catacombs such as those found in Paris,[9] Rome, Odessa, and Naples have been investigated by urban explorers. Some consider the Mines of Paris, comprising many of the tunnels that are not open to public tours, including the catacombs, the "Holy Grail" due to their extensive nature and history. Explorers of these spaces are known as cataphiles.

Storm drain outfall in Saint Paul, Minnesota

Entry into storm drains, or "draining", is another common form of urban exploration. Groups devoted to the task have arisen, such as the Cave Clan in Australia. Draining has a specialized set of guidelines, the foremost of which is "When it rains, no drains!", because the dangers of becoming entrapped, washed away, or killed increase dramatically during heavy rainfall.

A small subset of explorers enter sanitary sewers. Sometimes they are the only connection to caves or other subterranean features. Sewers are among the most dangerous locations to explore owing to the risk of poisoning by buildups of toxic gas (commonly methane, hydrogen sulfide, or carbon dioxide). Sewers can contain viruses, bacteria, protozoa, and parasitic worms. Protective equipment is recommended for people who enter sewers.[10]

Diesel trains in a tunnel of Metro-2 D6 line in Moscow, Russia

Exploring active and abandoned subway and railway tunnels, bores, and stations is often considered trespassing and can result in civil prosecution due to security concerns. As a result, this type of exploration is rarely publicized. An exception to this is the abandoned subway of Rochester, New York, the only American city with an abandoned subway system that was once operational. The Cincinnati subway is also abandoned but was never completed. London has a number of stations on the London Underground network that have been closed over the years, with Aldwych tube station a popular location for explorers.

Utility tunnel in the center of Zürich, Switzerland

Universities, and other large institutions, such as hospitals, often distribute hazardous superheated steam for heating or cooling buildings from a central heating plant. These pipes are generally run through utility tunnels, which are often intended to be accessible solely for the purposes of maintenance. Nevertheless, many of these steam tunnels, especially those on college campuses, have a tradition of exploration by students. This practice was once called "vadding" at the Massachusetts Institute of Technology, but students there now call it roof and tunnel hacking.

Some steam tunnels have dirt floors, poor lighting and temperatures above 45 °C（113 °F）. Others have concrete floors, bright light, and more moderate temperatures. Most steam tunnels have large intake fans to bring in the fresh air and push the hot air out the back, and these may start without warning. Most active steam tunnels do not contain airborne asbestos, but proper breathing protection may be required for other respiratory hazards. Experienced explorers are very cautious inside active utility tunnels since pipes can spew boiling hot water or steam from leaky valves or pressure relief blow-offs. Often there are puddles of muddy water on the floor, making slips and falls a special concern near hot pipes.

Steam tunnels have generally been secured more heavily in recent years due to their frequent use for carrying communications network backbone cables, increased safety and liability concerns, and perceived risk of use in terrorist activities.