Here are some nice images I encountered during research. Most of these are not interesting scientifically speaking, I just think they are pretty.

Time evolution of some 2D numerical error related to a wave equation. The value scale is of the order 10e-15 (machine precision), hence the "broken patterns" .

The level sets of the likelihood function associated to a well-chosen covariance function remind GPS localization methods. See this article for details and explanations.