15 heartbreaking photos of abandoned buildings in Baltimore and Philadelphia

There are more than 16,000 vacant homes in Baltimore and 40,000 vacant properties in Philadelphia.

These abandoned places are a goldmine for photographer Ben Marcin, whose eye was drawn to the lonely row homes left standing without neighbors.

"To me the houses first appeared as graveyard monuments," Marcin told Business Insider.

But as he began photographing more and more solo townhomes, he realized some weren't entirely empty. A run-in with one resident changed Marcin's perspective on the neighborhoods and the houses that remain there.

"The solo row houses became more than monuments to dying neighborhoods; they had become an act of defiance," he said.

Following are 15 images of the homes he captured, in Baltimore, Philadelphia, and Camden, New Jersey.