Summary of all results of the Delos (Environmental design of low crested structures) project. Objectives of Delos were (1) to provide an inventory of Low Crested Structures (LCS), (2) analyse LCS hydrodynamic an stability and their effects on morphology (3) investigate impacts of LCS (4) develop methodology for Integrated Coastal Zone Management (5) provide guidelines for the design of LCS. This report is the administative final report. For technical details is referred to the book "Environmental design guidelines for low crested coastal structures" by Burcharth et.al.Delo