The Concrete City was an early example of International Style architecture in the United States, built as company housing in 1911 for select employees of the Delaware, Lackawana and Western Railroad's coal division in Nanticoke, Pennsylvania. It was eventually taken over by the Glen Alden Coal Company who, uninterested in paying for required improvements and unable to demolish it due to its robust construction, abandoned the property in 1924. It stands to this day, albeit in extreme disrepair. Currently, the site is commonly used by military, police, firefighters and recreational paintball players for staged games.
In 1998, the Pennsylvania Historical and Museum Commission declared Concrete City an historic site.(Wikipedia)