Many grandmothers come complete with an attic or a basement full of hidden treasures. Dirty and ill-lit, it's a heaven for kids to secretly explore.
Now, take the same desire you had when you were six years old, project it some twenty or thirty years forward, and you're stuck with Haikyo. Haikyo is a Japanese word which literally means ‘ruins,' but as a verb it means exploring ruins and abandoned places. It's also called Urban Exploration. So, Haikyoist/Urbexer is a person who regularly undertakes haikyo or urban exploration.
Aral Sea - Ships in the Desert
Nuclear test sites, airplane graveyards, ghost towns, hospitals and sanatoriums, army bases, industrial plants, ice-bound russian wrecked ships, you name it. I guess you can call it a hobby pretty much anywhere you live - places which were once used and then left to slowly decay can be found in all corners of the Earth (even in the supposedly overcrowded Japan). It has its legal concerns, but doing something you're not supposed to has a strong appeal for many people.
Airplane boneyard, Mojave desert, USA
Doctor's Shack, Japan
Matsuo Ghost Town, Japan
Abandoned frozen ships, Kamchatka, Russia
US Air Force Base in Tachikawa, Japan
Osarizawa Chemical pools, Japan - chemical pools coloured blue with solution of copper sulfate
Ashio Dozan Ghost Town, Japan
Keishin Radiology Hospital, Japan
Sports World Theme Park, Japan