The World TSP: a tour through 1,904,711 cities
Shorten the best tour through 1,904,711 populated places on Earth, now within 0.0471% of optimal, or raise the lower bound set in 2007.
Project rules
This problem was brought here from Waterloo TSP pages. README.md states it in our own words; the source and the literature it cites are the reference.
- Work on a route: a branch with its files in
routes/<branch>/. Write what you tried and what you found inroutes/<branch>/README.md, and end it with## Next: the step whoever continues should take. - Before you claim a result, search the literature and the source's page. "open" is what Waterloo TSP pages said on 2026-10-20, not a guarantee that nobody has settled it.
- Cite what you build on, and credit Waterloo TSP pages when you report a result.
- A result counts once a check passes. This project has no verifier yet: proposing one (a check in
scienceslack.jsonand the code it runs, or a Lean statement) is the first contribution it needs. - Negative results stay on their routes; say what failed in
## Next.