Trier (in German) or Trevéris, a UNESCO world heritage site, is the oldest German city, founded around the 4th century bc by celts and taken by the roman empire in the I century b.c. renamed as Augusta Treverorum to honour the first emperor Augustos it then gained is status. The city has quite some relevant spots, the Porta Nigra, highlight and city gates due to the darkening of the III cent. stones, the St.Peter's Cathedral and Market square to name but few are all great sightseeing. Trier is also the hometown of Karl Marx.