International Rivers
A 2002 global atlas of international waters listed 263 rivers that cross or mark international political boundaries. This historical count is often paraphrased as “263 transboundary river basins”; those are related but not always identical counting units.
The number is not a timeless inventory of all present-day rivers. Newer catalogues count river and lake basins, use updated basin delineations, and apply different criteria: UN-Water cited 286 shared river and lake basins in 2021–2023 reporting, while its 2024 update estimates 313 rivers and lakes. Thus 263 is accurate only when tied to its historical source and definition.