The cathedral in Cologne is a UNESCO World Heritage Site. It is a massive, beautiful, gothic…read more architecture style cathedral. It has gorgeous stained glass windows and entry is free, just the tower climb & treasury is a small fee. The tower climb has a little over 500 steps if you're brave enough to take that workout. It is also known for housing the Shrine of the Three Kings.

First visited the cathedral on May 24, 2024 during our Basel to Amsterdam Viking River Cruise. Had…read moreonly a few hours in the city, and it was cold and rainy. Came back on June 22, 2025 during our Grand European Viking River Cruise. Wife and I went in briefly, wearing long pants, to meet the dress code requirements. This despite temperatures in the 90s during the great heat wave of 2025. In my younger days I would have tried taking the 533 steps to the top of the Cathedral tower, but wife was in no shape to do that. Our boat docked about 1.5 miles north of the Cathedral. We got a new vantage point to view the Cathedral at night from the river. Sailed past the lighted Hohenzollern bridge at 10:20pm with the Cathedral in the background. The new lighting done to save energy barely could be seen, compared to the old lighting which lit up the sky. Undoubtably I was the only person wearing a Hawaii hat visiting the cathedral that day.

Groß St Martin is a lovely church from the 1200s. While it is much more basic than the cathedral,…read moreit is still quite nice and is well worth stopping by as you walk through the old town. The church itself is pretty, but the really impressive part is the excavation Roman ruins in the basement. They aren't huge, but it is a unique experience, and they are well signed and maintained. The church is free, but there is a ,50-cent fee to walk down into the excavation (they have laminated descriptions in four languages, but the signs are in German). Definitely worth the ,50 cents to see the ruins!