A fall or perpendicular descent of the water of a river or stream, a cascade, a cataract
WATERFALL
The cyclical rise and fall of sea water, resulting from the gravitational attractive force between the earth and the moon
TIDE
An extensive tract of land, mostly level, destitute of trees, and covered with tall, coarse grass
PRAIRIE
A long or continued range of hills or mountains, the upper part of such a range
Ridge
The place where a body of water meets the land.
SHORELINE (also accept SHORE)
A chain or range of rocks lying at or near the surface of the water.
REEF
Small fertile area in a desert, irrigated by natural springs or other source of fresh water
Oasis
An opening in the surface of the earth or in a mountain from which smoke, flames, stones, lava, or other substances are ejected
VOLCANO
A place where water is collected and kept for use when wanted
Reservoir
a portion of land connected with a continent by a narrow neck or isthmus but nearly surrounded with water
Peninsula
Flat section of land higher than the surrounding area
PLATEAU
The altitudinal border above which trees do not grow.
TIMBERLINE
A fast moving river current caused by a moderate descent
RAPIDS
A current of water like a river, brook, or rivulet; a current of water in the ocean
STREAM
Large area of flat land
PLAIN
The bottom of a mountain
PIEDMONT
a tract of land overrun with heath; a marsh; a fen; ground covered with stagnant water
MOOR
A small cape, headland, or promontory; a tract of land extending into the sea
POINT
An extensive open plain or meadow; a plain destitute of trees
Savanna
A gap in a mountainous area suitable for passing through; a means of passage through a rugged area
PASS