Any structure or contrivance, as a mole, or a wall at the mouth of a harbor, to break the force of waves, and afford protection from their violence.

Large coastal structure designed to protect an area from wave action, either for navigation or coastal defence. Can be connected to or detached from the shoreline.

An offshore wall, built parallel or at an angle to the beach, that prevents the full force of waves from reaching a harbor.

Designed to protect the canal from destructive forces such as floods from lakes and rivers.