It took more than 600 years to build this giant structure, today named a UNESCO world-heritage site. The impressive cathedral holds the Holy Shrine of the Three Wise Men and countless precious treasures. In fact, in 2000, the cathedral treasures were placed in a historic vaulted chamber so visitors could view them easier. And if you have enough stamina to climb 509 steps, you'll also get a good view of Cologne on the observation platform.
We first headed to our hotel -- the beautiful, historic and elegantly appointed Excelsior Hotel Ernst -- to unpack and get our bearings. But Cologne is too exciting a place to sit still, so before long, we were off to discover what the third-largest city in Germany had to offer.
The hotel is ideally situated steps away from the picturesque Old Town with its interesting streets filled with shops, boutiques, restaurants, arcades and galleries that invite one to spend time shopping or sitting in the cozy outdoor cafes, relaxing and people-watching.
One of the things we most wanted to see was whatever was left of Jewish history in this town, which dates back to the Roman Empire, first becoming home to Jews perhaps as early as 70 C.E.
The medieval Jewish quarter existed until 1424, when the Jews were expelled from Cologne. The street in front of the building is the Judengasse; the medieval main synagogue, women's synagogue, hospital, bakery and community center stood nearby.
Today, all that remains of that medieval Jewry is the mikveh, which can be reached by descending 50 feet via a Romanesque stairwell. The pool is fed by the Rhine River, and dates from 1170.
Museums are plentiful in Cologne, some with international repute, such as the Museum Ludwig for Modern Art, and the Romano-Germanic Museum, with its collection of archaeological relics.
And as you walk around the intriguing streets, be sure and find the house of Original Eau de Cologne.
French for "Water of Cologne," the perfume company was launched in 1709 by Giovanni Maria Farina. French Revolutionary troops sent it home as gifts to the family. Napoleon was a particular enthusiast of the Farina product.
Not far away is Cologne's Modern Opera, which sits on the site of the 19th-century Glockengasse Synagogue, destroyed on Kristallnacht. The Offenbachplatz in front is named after the composer Jacques Offenbach, son of a Cologne cantor.
On the peninsula of the Rhine docks is the Imhoff-Stollwerck Chocolate Museum, Cologne's sweetest landmark. Its neighbor is the German Sport and Olympics Museum, a museum with lots of opportunities to participate.
If you tire of walking, enjoy a panoramic river cruise on the Rhine, one of the most picturesque and important waterways in Germany. We sailed up and down this stunning body of water for about an hour, listening to people speaking many languages, and to the ones with whom we could not speak, a simple smile was all that was really needed.