This volume contains a collection of expert views on the state of the art in Large Eddy Simulation (LES) and its application to complex ?ows. Much of the material in this volume was inspired by contributions that were originally presented at the symposium on Complex E?ects in Large Eddy Simulation held in Lemesos (Limassol), Cyprus, between September 21st and 24th, 2005. The symposium was organized by the University of Cyprus together with the Center for Turbulence Research at Stanford University and NASA Ames Research Center. Many of the problems that must be tackled in order to advance...