Königsberg

Königsberg was a historic city in Prussia (now Kaliningrad, Russia) known for its complex river system and seven bridges connecting different parts of the city. The challenge was to find a route that crossed each bridge exactly once, returning to the starting point. This problem inspired mathematician Leonhard Euler to develop graph theory, showing that such a route, or Eulerian circuit, exists only if certain conditions are met regarding the number of bridges connected to each land mass. Therefore, the Königsberg problem laid the foundation for modern graph theory and the study of network connectivity.