Sea terraces, which were originally part of the coastline or even were covered by seawater, have been created by being pushed upward by the movement of the earth and also by erosion. These geological forms are most frequently seen in the central and southern sections of the coast, with the sea terrace being broadest at Tulan, Chengkung, and Changpin.
這些原在海邊甚至海底的海階，是地殼漸歇性隆升加上海水的侵蝕形成的。海階多出現在東海岸的中、南段，其中以都蘭、成功、長濱的海階最為寬廣。