Third order landforms are formed on mountains, plateaus, and plains mainly by erosional and depositional activities of rivers, glaciers, winds, and waves. They are smaller features that form on second order landforms or on the surface of the Earth due to erosion and deposition. Examples of third order landforms include valleys, beaches, sand dunes, deltas, fjords, coasts, mushroom rocks, limestone rocks, spurs, gorges, ripples, and caves. These landforms are identified as local landscapes and there is no upper or lower limit to their size.