Decaying: The Carries Furnace are among dozens of abandoned buildings documented by Philadelphia photographer Matthew Christopher

Doing time alone: The rusting cell blocks of Essex County Jail in Newark, New Jersey, which have been unused since the prison closed in 1970 when a new one was built

Ruins: A building of the Julia de Burgos Magnet Middle School in Philadelphia, which was left to deteriorate after systematic neglect before closing in 2002

Matthew, 35, began his journey to document abandoned sites a decade ago while researching the decline of the state hospital system.

Matthew said: 'I want to be able to convey the respect, appreciation and awe that I have for the locations I visit. Trying to tell someone about a place conveys so little compared to being able to show it to them.

'My favourite part of exploring ruins is that to me, it is peaceful. I can focus on what I am seeing and experiencing rather than being wrapped up in my thoughts all the time.

'Discovering new or intriguing places, finding something you know not many people have seen, or managing to get permission to somewhere you'd really like to see are also a lot of fun.

An undisclosed prison: Matthew says he likes discovering 'new or intriguing places, finding something you know not many people have seen'