A Surface-Plasmon-Polariton (SPP) is a coupled mode between an electromagnetic wave and an electron density wave that propagates along a metallic surface. Similar to “conventional” light, the SPPs can be superimposed and interfer. An appropriate method to investigate the resulting interference pattern is scanning near-field optical microscopy, where a sharp tip is raster-scanned along the metallic surface. The metallic tip acts as an antenna, converting the SPPs into light, which can be detected in the far-field. The short movie shows the measured interference pattern of several SPPs launched via circulary polarized light at the edges of a hexagonal single-crystalline gold platelet, with an approximate diameter of nine micrometers.