Comparing the cathedral at Aachen today with Dürer's picture, one can see that the roof of the central octagon is different. In fact the original burnt down in the great fire of Aachen which destroyed 90 % of all buildings in the town in 1656. The roof was replaced by a more baroque one, but as almost the whole of Aachen had to be rebuilt, they built the roof from
freshly cut oak wood, and when this dried, the roof got a funny twist that is still visible.

There is another story about a Dürer drawing of the town-hall in Aachen. As with his drawing of the cathedral, this was very accurate. The great fire destroyed the spires of the two towers at either side of the town-hall, and afterwards the spires were rebuilt in baroque style. However, while the baroque roof of the cathedral survived the last war, in which again a large part of Aachen was destroyed, the spires of the town-hall did not. The towers were first given a provisional shelter roof, but about 25 years ago it was decided to rebuild them properly.
Then there was a long discussion about whether to rebuild the baroque spires or the original ones which were known exactly from Dürer's drawing. In the end Dürer won and so the spires that you can see today were built 20 years ago from Dürer's drawings.

Joachim Neubüser, RWTH, Aachen.