I found this map in a Reddit post. Please note that the post itself has way more information in the comments than I could possibly provide here.

What struck me about this is that Regensburg was the largest city in Germany, and one of the nine largest cities in Europe altogether. I grew up in Regensburg, and I know the city well. I always knew it was one of the oldest cities in Germany. Incidentally, it was also one of the few that did not get bombed out in WW II, so many of the old churches and buildings are still intact. I remember clearly as a boy walking the city and never being much impressed with the “Altstadt” – the old town, but that’s what I had grown up with, so I knew of no other reality.

I have a few photographs I took during a visit in March of 2014 . Here is the center of the city with the famous cathedral. The towers are 100 meters high.

The very oldest settlements of the city can be dated back to 5,000 years BC.  Regenburg was a Roman fort with the name of Castra Regina 2,000 years ago. There are still remnants of the old city wall in downtown, right there for anyone to view – and touch. As a child, I was not impressed much, but as an adult, and particularly an American, going back and  walking the old city streets, I always have a sense of awe.

Regensburg is located at the northernmost tip of the Danube. It is navigable there, but only for a few miles upstream before it gets too rough. Two smaller rivers, the Regen and the Naab, join the Danube at Regensburg from the north. Due to this important strategic location, on the trade routes between Paris, Kiev and south to Venice, the city was an important crossroads and a center of trade for millennia. With a population of over 40,000, the wealthy city was larger than Rome, Paris and Cologne at that time.

It’s astonishing that Rome didn’t even make this list. Rome had a population of about 30,000 then, down from more than a million in the heyday of the Roman empire. Baghdad was the largest city of all on this map.

In 1135, a stone bridge was erected there called die Steinerne Brücke, which is still standing to this day. When I was a boy, there was still two-way automobile traffic allowed across the bridge, but it was closed decades ago and only left open to foot traffic. I walk over the bridge wrapped in nostalgia every time I visit Regensburg nowadays. Here is a photo I took in 2014, walking on the bridge:

At the northern end of the stone bridge is the old historic sausage kitchen, called die Historische Wurstküchl. At an age of 500 years it is one of the oldest continuously operating restaurants in Europe. They make their bratwurst the same way now they did 500 years ago, and I recommend a visit to any tourist. One notable fact is that the restaurant gets flooded every few decades, with the water of the Danube reaching halfway up the first story of the building. When you look carefully on their website, you will see some signs in the restaurant, showing how high the water was:

In the above picture, you can see my red arrow pointing on a plaque in the wall: Wasserhöhe means water level. The date of March 27, 1988 shows when the water was up to that point. But this has been going on for centuries as the Danube floods from time to time, and they just clean up and continue with business.

Here is one more view of the city from the bridge:

And that’s what went through my mind when I stumbled across that Reddit post.