This lecture introduce on Coastal Environments: Sand Dune Systems. In this presentation, explain a little about their formation. This needs to be understood in order to understand the processes that follow. Classification is needed to identify specific types of dunes as each has differing characteristics and therefore different properties. The UK provides ideal conditions for the formation of sand dunes which is why they are relatively abundant. It is because they are so common that they are important in ecological and geographical terms. Examples of coverage: Ynyslas near Aberystwyth – spit dunes.