The ocean monuments from the Release 1.8 Minecraft update introduce 4 new blocks (prismarine, prismarine bricks, dark prismarine, and sea lantern), 2 new mobs (guardians and elder guardians), and 2 new items (prismarine shards, prismarine crystals). You can use these items to craft 3 of the 4 new blocks.
What is a natural levee and how is it made? -Natural Levees are formed by the river in its process of flooding -A natural levee is formed by a deposit of sand or mud built up along, and sloping away from, either side of the flood plain of a river or stream.
Small unsteady spoil banks/ levees can be built up to form a 'bowl' shape. Then with the help of dredges, soil can be pumped in and marsh grasses planted. Once the marsh grasses build up, levees will begin to collapse creating a new vegetated marsh area.