Five cities that grew up on a fork in the water — where one current runs into another, and the trade, the temples and the skylines all crowd around the junction.
The Rhône and the Saône join at the tip of the Presqu'île. Rome made Lugdunum the capital of the Gauls precisely because of that junction, and the theatre it cut into Fourvière hill still stages concerts two thousand years on.
The Ganges and the Yamuna meet at the Triveni Sangam, where tradition adds the invisible Sarasvati as a third. The 2025 Maha Kumbh here logged visits counted in the hundreds of millions over six weeks.
The Han joins the Yangtze here, splitting the city into Hankou, Hanyang and Wuchang — three towns merged into one municipality in 1927, whose name is stitched from two of them. The 1957 road-and-rail bridge was the first ever built across the Yangtze.
Just downstream, the coffee-black Rio Negro and the sandy Solimões run side by side for some six kilometres without mixing — different temperatures, speeds and densities — before finally merging into the Amazon.
The Allegheny and the Monongahela merge at the Point to form the Ohio, which runs 1,579 km on to the Mississippi. Washington's journal called the fork "extremely well situated for a fort" — and two empires fought a world war over it.
Think you'd have found them? Play today's expedition, or replay this one from the archive.