I don’t know when I first heard the term ‘industrial archaeology’, but like cults, pyramid schemes and the history of California, it has since become an obsession of mine. Loosely speaking, it’s the study of material evidence associated with the industrial past, from old bridges and towpaths to decommissioned mines and power stations. But what I really love are the relics - the individual artefacts that have been left behind and abandoned to nature. Rusting machinery, segments of wall, follies, signposts, pillboxes, railway sleepers; the