There are no formal tours through these forbidden facilities, so urban exploration is technically trespassing. Some adventurers thrive on the adrenaline rush that comes from eluding security guards. Occasionally, urban-exploration expeditions resemble video games such as Splinter Cell, in which players sneak past enemies instead of engaging them. But whereas the heroes of those stories are spies, urban explorers are often curious kids with a unique way of expressing civic pride.
"Urban exploration stresses history, and learning about what a building was used for in the past can be fascinating," says Lydia, a student who has taken clandestine trips to train tunnels and grain elevators. (The explorers offered only their first names.) "The history of a building ties into the history of the city and the people."
"The discovery of a new structure is one hell of a thrill," adds Max, the 17-year-old leader of a local urban-exploration group. "It's as if life suddenly stopped. Everything remains in the same place as it was left years ago."
Before infiltrating a target, explorers scout the location, using a global-positioning device to note landmarks. An expedition requires an extensive equipment list, with a flashlight (including backup batteries) and a personal respirator (to guard against asbestos) among the most essential items.
Lydia takes her camera as well. "Buildings are given life by those who inhabit them, and when those people leave, nothing remains except their echoes," she says. "But those echoes of all the joy and grief those people experienced give the building a voice of its own. With photography, you get a chance, often the last, to capture that."
Urban explorers might share photographic proof of their finds with the public, but they're much less likely to give directions to the sites to strangers. Online, they share horror stories about untrustworthy associates damaging or squatting in their favorite haunts.
"People vandalize anything," says Paul, who has five years' exploring experience, none of which he will describe in detail. "It's so sad to go into a once-beautiful place and find everything smashed."
If urban exploration had a governing body, purists could apply for licenses, flash them when confronted and continue with their harmless investigations. Going official, though, would cost the activity its well-intentioned-outlaw overtones, which would in turn damage its Indiana Jones appeal.
"Trespassing is enforced because of vandalism, theft and injury liability, and we avoid all of those situations," Max says. "If we were to damage a site in any way, it would contradict the reason we're there, which is to collect and preserve as much information as possible about the building so its existence isn't completely lost when it is demolished. We expect authorities to be understanding."