1. Sea Cliffs: These are steep, vertical rock faces along a coastline, formed by the relentless pounding of waves against the cliff base.

2. Sea Caves: Waves can exploit weaknesses in rock formations, carving out hollows and tunnels into the cliff face. Over time, these can become large enough to be called caves.

3. Sea Stacks: As waves erode a sea cliff, resistant rock formations can be left standing isolated in the sea, creating dramatic columns of rock.

4. Wave-cut Platforms: The constant erosion at the base of a cliff can gradually create a flat, wave-cut platform at sea level. This platform represents the former cliff face.

5. Arch: When a sea cave is eroded through from both sides, it can form a natural archway. These are often found in areas with softer rock types.