Detailed schlieren and laser lightsheet visualizations of the near wake of micro vortexgenerator (MVG) revealed large structures that were different from those of the undisturbedturbulent boundary layer. These structures were attributed to the rapid breakdownof the primary trailing vortex pair. The breakdown was thought to arise from a cylindricalKelvin–Helmholtz-like instability surface. The structures appear to be hairpin or ring-likein nature that showed eruptions into the freestream flow, entraining it.