(WIRED) — Will Ellis ignored his first "no trespassing" sign in 2012 when he ducked through the fence surrounding an old warehouse in Red Hook, Brooklyn.

He started photographing the rotting interior and was immediately hooked.

"I'm not a daredevil at all, but the first time I snuck in, there was that rush of adrenaline and sense of adventure," Ellis says. "I was also fascinated by the visuals inside. As a kid I loved all things creepy—Halloween was my favorite holiday and that's something I never grew out of."

From the creepy to the bizarre, Ellis' exploration of the derelict and decrepit has lead him to document nearly 50 locations across New York City and beyond.

The images chronicle forsaken schools, asylums, and forts, along with railroads and waterfronts. He updates his popular blog constantly, and a collection of 150 images has been published in Abandoned NYC.

Ellis has become somewhat of an expert at discovering the city's hidden ruins.

He gleans a lot of information from other "urban explorers" who post their findings online.

He also uses Google Earth — if he sees a building with a collapsed tree outside or what look like abandoned cars, it's a sure sign no one's inside. In three years of urban spelunking, he's somehow avoided being arrested.

There are occasional run-ins with security guards, but he usually leaves when they tell him to and that's that. "Getting in is easier than you think," he says.

The photographer usually packs a digital camera, tripod and a couple architectural tilt-shift lenses to really capture the buildings in all their crumbling glory.

Light is key. Cracks in boarded windows and holes in the roof often create contrasty, saturated light you don't see anywhere else. To catch the tricky light, Ellis sometimes makes multiple exposures and combines them in Photoshop. "The light is what makes these place so mysterious and gives them a particular feel," he says.

While some might call the work classic "ruin porn"—fetishizing urban decay in cities that have hit hard times—Ellis takes a more anthropological view.

The photographer is more interested in the structure's vanishing history and the stories it tells.

Ellis puts a lot of research into each location, pairing the gorgeous, gritty images with equally fascinating tales of their past. For some buildings like the Harlem Renaissance Ballroom or Williamsburg's Domino Sugar factory, the photos are often a memoriam before they are demolished.

As New York continues its ceaseless redevelopment, Ellis says it's becoming harder to find new spots to photograph.

He now travels beyond the five boroughs, including places like Long Island and New Jersey. Ellis says he had to move further afield if he wanted to keep finding material for his blog. The search is never-ending.

"At this point I've mostly run out of locations that are already discovered so I'm definitely having to dig a little deeper," he says.