Climate change and the associated projected rise in sea and ocean levels is one of the immediate and more significant threats to the functioning of modern cities. The need to exist in endangered zones is forcing decision-makers to take a new approach to both protecting existing cities and creating new concepts for coastal cities. The article presents an analysis of two urban trends for building sustainable coastal cities. The first group - urban metamorphosis - describes actions taken in the area of existing cities and affecting a significant change in their image. The second group - urban creation - refers to the creation of new urban structures and introducing them in an innovative way into a hitherto non-urbanized environment. Implemented solutions to both existing and newly designed cities can build new quality and new typologies of public spaces by basing them on ecological and sustainable development principles. Therefore, they can become an element of urban marketing and a basis for building a new identity for cities in the context of ongoing climate change and the need for safe areas for future urbanization.