Speyer Cathedral

The Speyer Cathedral is a building of overwhelming size. Its four towers rise beautifully over the city. The historical significance with the imperial tombs is impressive.

Panoramic all-round view and the gigantic cathedral from above.
The 6 euros are a bit steep, but it's worth the climb.

According to Wikipedia, a legend says that Konrad laid the foundation stone for the Limburg monastery (near Bad Dürkheim) early in the morning, then rode to Speyer with his wife Gisela and his entourage to build the foundation stone for the cathedral and the Saint Johannes monastery on the same day to lay the later St. Guido pen. In order to bring the amount of stone and wood required for the construction to Speyer, a canal was built from the Palatinate Forest to the Rhine. This channel could mean the relocation of the Speyerbach, which was moved a few kilometers to the south in the Middle Ages at the latest to supply Speyer.