The north coast of Java Indonesia is an area threatened by erosion due to rising sea levels triggered by climate change. Sayung District, Demak, which experienced severe erosion impacts. Restoring lost sediment is an effective way to stop erosion processes and restore a stable coastline. In this chapter, the strategies of coastal protection carried out are presented with the ultimate goal of restoring the natural defense of the coast, namely, mangroves. The first step is to build a coastal protective building to reduce waves and create calm waters. It will accelerate the sedimentation process so that new sludge-substrate land will be formed that is suitable for mangrove ecosystem growth. This coastal erosion mitigation activity is an effort to increase the resilience of coastal areas from physical aspects that cause deterioration or reduction of coastal functions. The concept of building together with nature has a very high technical, socioeconomic, and environmental feasibility because it is a coastal engineering approach as one of the solutions to the problem of sustainable erosion.