Psychogeography has been described as "the hidden landscape of atmosphere, histories, actions and characters which charge environments... The lost social ley-lines which make up the unconscious cultural contours of places." The term was first used by French members of the Situationist International, who, among other events, carried out derives, unguided wanderings through the streets of (at first) Paris. The term was taken up by, and the philosophy an influence on, British writers such as Iain Sinclair and J.G. Ballard.