The formation of a wave-cut platform and a stack are illustrated. 'Hard' coasts and 'soft' coasts erode at different rates and form different features. The formation of a wave-cut platform created when a cliff recedes is illustrated. Weaknesses at the base of a headland are increased through erosion. Over time, gaps in the rock grow to form first a cave, then an arch, culminating in the formation of a stack.

First broadcast:
17 October 2007

Students could annotate photographs of coastal features and maps, explaining the formation of wave cut platforms, bays, arches and stacks. They should demonstrate use of the correct terms for the processes involved and the features.