ABSTRACT: Cities, which are established on sea cliffs, like Antalya, suffer some instability problems. The most important reason of cliffi nstability is wave erosion. At the base of cliffs wave impacts results in erosion. In thinly bedded rocks, this removes the support at the base and above rock layers fail due to high tensional stress. Cliff retreat is observed as a result of rockfall. Instead, in massive rocks, notches are developed at the base of the cliff. As a result ofu ndercutting tensional cracks occur above the cliff. This is the beginning of "tilt instability As the rock block is tilting, notch tends to be closed and turn in to a "crash zone ". As centre of gravity shifts through the sea, deformation increases in the crash zone, and additional deformation in the crash zone result in a new shift ofc entre of gravity. This process continues until the toppling of rock block completely. The process between opening of tension crack and toppling is called “secondary toppling mechanism ”. Factors affecting rate of cliff erosion and retreat are; sediment transportation, wave direction and intensity, properties of rock material and rock mass, precipitation, urbanization and construction facilities. In this paper, erosion and retreat mechanism observed in Antalya sea cliffs will be explained. Erosion and retreat conditions of cliffs around A tat ürk Park. School of health. Yacht harbour-Iskele Street, Old Lara Street and Bambus Beach will be explained as case studies.