Dreiländereck

A pair of 19th-century granite markers symbolically record where the state boundaries of New York, New Jersey, and Pennsylvania intersect.

This original Mason-Dixon line cairn placed in the 1760s was put in the wrong location because of the gravitational pull of the Allegheny Mountains.

Where Saint-Martin ends and Sint Maarten begins (or vice versa).

An iron monument on the 120th meridian as surveyed, one of only four marking the boundary between Nevada and California north of Lake Tahoe.

This marker identifies the location where three states converge.

A small granite monument marks where the borders of three countries meet.

The marker offers a rare chance to be in four U.S. states at once, though there's some controversy over its geographic accuracy.

This human-shaped statue is actually a geodesic station.