This document defines 20 geographic landforms and ocean floor features. It describes cliffs as steep rock formations, beaches as areas of sand or pebbles along a shore, and peninsulas as areas of land mainly surrounded by water. It also defines isthmuses, capes, islands, gulfs, bays, continental shelves, continental slopes, abyssal plains, mid-ocean ridges, ocean trenches, and various landforms such as mountains, mountain ranges, valleys, plains, plateaus and basins.