Travelers are voting Engelsberg Ironworks, Mehmed Pasa Sokolovic Bridge and Derwent Valley Mills as the best of 1491 key buildings in Europe. Also popular are Ir.D.F. Woudagemaal in Netherlands, Volklingen Ironworks in Germany and Stoclet Palace in Belgium. Want more? Check out our map of key buildings in Europe or these 2 key buildings in Vatican City.