CNN  — 

As an airline pilot, Belgian-born Henk Van Rensbergen was used to traveling the world. But he found a great way to supersize that passion: hunting for the most wonderful, secret, haunting abandoned places.

“I bought my first camera at age 16 and soon started making photos just to prove to my friends that I had been inside this abandoned factory or that off-limits disused hospital,” he said in an email. “Soon my attention shifted to actually capturing the atmosphere inside these places.”

For the past 25 years he has scouted countries the world over and gotten in touch with fellow urban explorers online to find the best spots to immortalize. With several books to his name, he considers himself a pioneer of the urban exploration genre. (“Although to find the founder of it, you have to go as far back as Piranesi, an Italian artist who lived from 1720 to 1778,” he said.)

But why are we so fascinated by decaying ruins, empty roads and vacated buildings?

Van Rensbergen's latest book is titled simply "Abandoned Places."

“It’s probably a cocktail of different things, such as living your childhood fantasies of discovering a forgotten world, a bit of melancholy and a healthy sense of adventure,” he said.

Is it ever dangerous? “Yes, it could be, especially if you break your way in, if you invade privacy, steal or break things… behavior that is not tolerated by educated explorers.”

Browse the gallery at the top of the page to see some of Van Rensbergen’s best photos.