The Dutch polder landscape still needs to be defined again. This time, the transformation is no longer to make the delta area habitable through reclamation and management, and to improve agricultural efficiency through land consolidation, but to respond to the challenges brought about by today's extreme climate change and population growth. The goal is to form a more flexible and more livable landscape that is more inclusive to people, plants, and animals. This article discusses the formation process, status quo, potential, challenges, and possible future of the Rotter River Basin, a representative of the polder landscape. The abstract design principles behind the proposal described in this article also inspire polder landscapes in other parts of the world.