Germany is home of many fascinating attractions from the tallest cathedral in the world, to its numerous castles. Germany's cathedrals are well-known for their Gothic architecture. All of Germany's architecture has very unique details. The stain-glass windows in the Ulm Cathedral simply take your breath away with all the precise details. It's interesting to think of all the long and hard work that was put into cathedrals such as the Ulm, Heidelberg, and the Aachen Cathedral.