Zoey Poll writes at Eye On Design how “For Decades, Cartographers Have Been Hiding Covert Illustrations Inside of Switzerland’s Official Maps”. She argues that these hidden drawings are a kind resistance of Swiss cartographers and their mission to draw as accurate as possible:

These barely-perceptible apparitions aren’t mistakes, but rather illustrations hidden by the official cartographers at Swisstopo in defiance of their mandate “to reconstitute reality.” Maps published by Swisstopo undergo a rigorous proofreading process, so to find an illicit drawing means that the cartographer has outsmarted his colleagues.

(Via Kottke)