Trier, cathedral
The construction of the cathedral of Trier was started by the Roman emperor Constantine (306 -337), in 326.
When you don't see the puzzle, please check whether your device can handle html5 or java. Read here why the puzzles look different and which problems there can be
When you don't see the puzzle, please check whether your device can handle html5 or java. Read here why the puzzles look different and which problems there can be