Residual landform, also known as relict landform, is a type of landform that was formed as the remains of an ancient landscape, surviving burial or destruction to become part of the current landscape. Modified climatic conditions are often the cause of residual landforms, but they may also be caused by volcanism or crustal uplift and down warping. Extinct volcanic cones, inactive stone rivers from climates on the edge of glaciers, disconnected and abandoned drainage system bits, abandoned strandlines from more humid climates, fixed sand dunes from drier climates, coastal terraces from high sea levels, and plunging sea cliffs from lower sea levels are examples of residual landforms. The percentage of residual landforms in a given landscape and the value given to relict landforms by various geomorphologists can differ dramatically.