A KNOLL is a small natural hill, typically one that is round or conical in shape. It is usually lower than the surrounding land and is often covered with trees or shrubs. Knolls are often found in areas of low relief, such as on the edge of a plateau or in a valley. They can also be found in areas of higher relief, such as on the side of a mountain. Knolls are often used as landmarks or points of reference in navigation.