Where is it? (p. 100); Position in space, a cornerstone geographic idea ( p. 271); Relative location: position expressed in terms of one or more known locations (p. 59); absolute location: Position expressed in terms of a coordinate system or mathematical grid (p. 59); . . . the concept of location is surprisingly difficult to communicate without employing at least one other spatial concept, such as distance, direction, adjacency, or enclosure (p. 100)