Definição: A landform that extends above the surrounding terrain in a limited area. A mountain is generally steeper than a hill, but there is no universally accepted standard definition for the height of a mountain or a hill although a mountain usually has an identifiable summit and a local relief of more than 300m.
Definição: Gravel is an environmental material which is composed of pieces of rock that are at least two millimeters (2mm) in its largest dimension and no more than 75 millimeters.
Definição: A feature shaped by the dissolution of a soluble layer or layers of bedrock, usually carbonate rock such as limestone or dolomite. These landscapes display distinctive surface features and underground drainages, and in some examples there may be little or no surface drainage.