Cologne is a true jewel of a city here in Germany. Unlike Frankfurt, which was also heavily bombed during WWII, Cologne managed to reconstruct the majority of the old city using the original pieces of the buildings that were bombed. At the heart of the city is the Dom- the cathedral. This was the tallest church in the world until very recent times, and was in fact the tallest building in the world until the construction of the Washington Monument was completed.