Discover trier one of germanys oldest cities at your leisure on a city sightseeing hop on hop off tour as you explore the city by open top double decker bus put together your own day of sightseeing and visit the places that interest you most hear about standout sights from the audio commentary and pay visits to konstantin basilika karl marx haus and trier roman amphitheater among other attractions the tour ticket is valid for 24 hours from first use