TetraPOT is a sustainable sea defense system made of concrete, organic materials and plants. The typical sea defense system is composed of man-made concrete objects, known as tetrapods. Due to the constant thrashing of water, these structures eventually erode. At the same time, natural sea defense systems, such as trees, are often inadequate, particularly against the extreme weather associated with climate change. TetraPOT combines the advantages of both, providing an innovative concrete sea defense system that contains and nurtures the growth of plant life. Randomly distributed TetraPOTs along coastlines will eventually interlock to create a long-lasting sea defense of growing trees and roots that help keep the blocks in place.