On a shoreline where there are different types of rocks, some more and some less resistant to erosion, sediments such as sand and silt will be carried away, leaving behind the more resistant rocks. A bay will form where the less resistant rocks are eroded away and it leaves behind land on three sides. The water in a bay has less waves than the water on the outside of the bay in the ocean. Bays provide a safer area for swimming as they are calmer. A headland is surrounded on three sides by water. Due to waves breaking along the coastline, erosion occurs and other landforms such as caves can form on a headland. Headlands are characterized by high breaking waves, much erosion and cliffs. A bay has less wave activity in comparison.