About 300 feet up in Mill Hell, an abandoned mill in Minneapolis, Matt sat on a ledge with his feet dangling in the air and looked at the panorama below him. In his left hand he held a GoPro camera, which showed the Minneapolis skyline in the distance.

Then he stood up, took his phone from his pocket and snapped a selfie.

"I really did not expect anything all that great," he said. But when he got to the top, "I turned around, and the view is amazing."

Matt is 16. He agreed to speak about his hobby — known as urban exploring — on condition that his last name be withheld, because the activity involves breaking trespass laws.

His first outing came last September, when he climbed the ladder at Mill Hell and recorded every step. A magnet for urban explorers, Mill Hell is part of the Southeast Minneapolis Industrial Area, near TCF Bank Stadium.

Matt knew his friends at school would see the video, so he focused on walking around and getting good shots, such as the panoramic scenes of Minneapolis and the spray-painted artwork all over the mill.

"The first time I actually went up there," he said, "I really wanted an adrenaline rush, and that is exactly what I got." A friend edited his video and uploaded it to YouTube.

When his parents saw it, they were amazed. But they worried when they saw videos of him dangling from cranes by one hand.

That fear is not misplaced. The hobby can be deadly.

Bunge Tower circa 2010 Courtesy Courtney Celley

Earlier this month, Emily Roland, a 20-year-old woman from Cottage Grove, died after a fall from the Bunge Tower, an abandoned grain elevator in Minneapolis' Como neighborhood.

Roland was a sophomore in the University of Minnesota's College of Liberal Arts.

And in 2006, at least two people, including Germain Vigeant, a 20-year-old University of Minnesota student, fell to their deaths while climbing abandoned elevators.

Vigeant was exploring the Bunge Tower at night without a flashlight. She was drunk when she fell through an open hatch on the 10th floor of a grain silo.

Filmmaker Melody Gilbert, who made the documentary "Urban Explorers: Into the Darkness" in 2007, said the explorers she encountered exercised caution.

"I never ever, in the entire time I went exploring, went with anyone who'd had a single thing to drink or had an altered state of mind," Gilbert said. "They would never drink before they would go exploring."

Gilbert described two kinds of urban explorers.

"Half of the people are in it for the excitement and the thrill and getting into places and the challenges," said Gilbert.

The other half, she said, are mostly photographers and people who appreciate architecture, the "beauty of decay" and the historical nature of old buildings. As a filmmaker, Gilbert said, she relates more to the second group.

After exploring inside Bunge Tower in 2010, photographer Courtney Celley wrote about the experience on her blog: "There were a lot of uncovered holes that you could fall through into a silo." Courtesy Courtney Celley

Colleen MacDonald, an urban explorer in Minneapolis who studied architecture, said she is motivated by a desire to take photographs and document the history of dilapidated structures.

"My interest in going to take photographs of them is maybe to highlight something that somebody would miss in their everyday life and draw some attention to some of the beautiful areas of Minneapolis and St. Paul," she said.

MacDonald said she's careful when she enters abandoned buildings. She brings along a light, goes with friends or tells people where she's going, and always keeps a cell phone with her.

"When I was going out to take photos I never drank or consumed any sort of alcoholic beverages or engaged in any kind of risky behavior," she said.

Despite the inherent risks involved in urban exploring, Matt, the teenager, said he drives around with his friends after school until they find a spot that they can get into and then climb to the top.

"I just do it," he said. "I think it's just fun."