View of the Stone Bridge (Steinerne Brücke), Regensburg

When visiting Regensburg you definitely shouldn't miss it: A masterpiece of medieval architecture in Germany - The Stone Bridge.
Along with Regensburg Cathedral, it is the city's most important landmark and was certainly one of the reasons why Regensburg was included in the UNESCO World Heritage List. The Stone Bridge, which connects the old Bavarian district of Stadtamhof with Regensburg's old town, was considered a real wonder of the world in the Middle Ages. It was built in just 11 years, probably between 1135 and 1146. The busy trade traffic of Regensburg, an important economic center in the Middle Ages, required the permanent river crossing. So the council and citizens decided to build the building. For almost 800 years, until 1935, it remained the only bridge that served as a reliable Danube crossing in Regensburg and the surrounding area. The impressive structure spans the river in round stone arches at around 300 meters.

Along with Regensburg Cathedral, the Stone Bridge is the most important landmark of Regensburg. When construction began in 1135, the Stone Bridge is considered a masterpiece of medieval architecture and the oldest surviving bridge in Germany.

The current "Iron Bridge" was completed in 1991 and connects Regensburg's old town with the Lower Wöhrd district. The bridge had several wooden bridges as predecessors since the 15th century and crosses the southern branch of the Danube. Due to its direct connection to the historic old town, a delicate steel structure with the load-bearing capacity of a future tram line was chosen for the new bridge in 1991.The oldest reference to a previous wooden bridge at this location can be found in a parchment manuscript mentioning a severe ice drift in 1431/32, which destroyed the bridge. Another manuscript lists 1511 as the year the bridge was built, although this was likely only the construction of a new bridge following an ice jam.More information about the "Iron Bridge":
de.wikipedia.org/wiki/Eiserne_Brücke_(Regensburg)