These wooden posts are what remain from the old sea wall in Capitola, California. Sea walls are built as a form coastal defense constructed. The purpose of which s is to protect areas of human habitation, conservation and leisure activities from the natural action of tides and waves. As ocean levels rise, there is speculation that the financial cost of coastal flooding will far exceed the costs of not building protective sea walls. Yet, the ecological changes to the natural shores as a result of sea walls come with a hefty price tag as well.