**Conjecture**Does every Jordan curve have 4 points on it which form the vertices of a square?

A Jordan curve is a continuous function from the closed interval to the plane with the properties that is injective on the half-open interval (i.e., is *simple*) and (i.e., is *closed*).

## Bibliography

[M] Meyerson, M.D., Equilateral triangles and continuous curves, Fund. Math. 110, (1980), 1--9.

* indicates original appearance(s) of problem.