While playing a multiplayer game of Civilization VII with friends, player Derpy_inferno encountered a rare map generation result. On a standard-sized "Pangea" map, a navigable river runs from west to east through the center of the continent, nearly connecting both sides.
Based on the screenshot, the main channel of this river spans approximately 20 tiles. Including the lake to the northeast and the river segment leading to the ocean, its length is around 23 tiles or more. Since the full western end is not visible in the screenshot, the river's total length cannot be determined at this time.
The player has established multiple cities along the river, with some city names referencing Star Wars and Game of Thrones. Navigable rivers play a more significant role in Civilization VII than in previous entries in the series, allowing ships to move along them and providing advantages in building layout and trade for riverside cities.
Many players believe that rivers generated on standard maps are often short and fragmented, so this "mega-canal" that nearly spans the entire continent has drawn attention. Some players have suggested that Firaxis add an option for ultra-long rivers to the map generation settings. However, this is merely a rare case discovered by the community, not an officially added mechanic. Its cause remains unclear, and it is uncertain whether it can be reliably reproduced.