found old Königsberg on the map …
Königsberg was the capital city of the Kingdom of Prussia until about 1701, when the Prussian capital changed to Berlin. Aside: the Seven Bridges of Königsberg problem was solved by Swiss mathematician Euler in 1735, which is regarded as the first “result” or first paper in graph theory. Königsberg was almost destroyed in 1945. It now has the name Kaliningrad, and although part of Russia, is not connected to Russia (an exclave).
