[JadeNB]

> Others had been destroyed in WW2 and/or replaced with modern, larger bridges.

I read a while ago that the destruction had actually rendered the bridges problem soluble (that is, that there is a modern Eulerian path); but I don't know if that was true at the time, or is still true.

[OscarCunningham]

From Google Maps it seem like it currently is possible to walk all the bridges, although you can't end where you started. Two of the original bridges have gone, two more have been built (not in the same locations as the destroyed ones), and there are two additional bridges that are within the city limits now but wouldn't have been in Euler's time.

[JadeNB]

I love it: the nine new bridges of Königsberg! (It would never have occurred to me to check on Google Maps; thanks!)