Assertion: breakwater | /r/HasProperty | built of concrete
Facets:
Source sentences:
text: Seawalls are structures built of concrete, wood, steel or boulders that run parallel to the beach at the land/water interface.
text: A seawall can be built of a wide range of materials, including concrete, and can be finished in a wide variety of materials, including wood retention (primarily used for freshwater structures), composite, vinyl and steel.