Oxymoronic Sign

perimeter

noun
The border or outer boundary of a two-dimensional figure.

center

noun
Geometry. the middle point, as the point within a circle or sphere equally distant from all points of the circumference or surface, or the point within a regular polygon equally distant from the vertices.

oxymoron

noun
A figure of speech by which a locution produces an incongruous, seemingly self-contradictory effect, as in “cruel kindness” or “to make haste slowly.” ... or "Perimeter Center."