A narrow ridge of offshore sand rising just above high-tide level, running parallel with the coast but separated from it by a lagoon, is called a barrier beach. (The term is frequently, though incorrectly, used as a synonym for barrier island, a larger and more complex coastal barrier, of which sand makes up a relatively small portion.) The more nearly spherical a grain of sand, the older it is, according to writer Annie Dillard, who also points out in her book For the Time Being that little or no sand lies beneath the deep oceans. Gustave Flaubert was somewhat obsessed with the movement, ubiquitousness, and all-conquering nature of sand. In all his works it possesses great signiﬁcance.