Wordsworth refers to the sands of Morecambe Bay, a large expanse of intertidal mudflats, some 190 square miles of which become exposed at extreme low tides. People have been traversing the estuary for centuries, and accounts of the sometimes-treacherous crossing appear in guidebooks known to Wordsworth. Photo: a view of the Sands near Ulverston (Paul Westover). See also note to p. ix.