Europe has a jump on American for ancient towns that were left to rot as citizens moved on from mining area to mining area or disasters befell them and created a mass exodus. Sometimes war causes blight, other times economics. It's the crumbling stone remains of many of these locations that make them seem positively ancient.
Oradour Sur Glane, France
Abandoned castle, Belgium
Abandoned Factory in Finland
Abandoned amusement park, Germany
For some truly haunting and beautiful (some of the best I believe) photos of abandoned Europe locations, check out this site.