In short: dark tourism is travel (for leisure rather than for professional reasons) to sites that are in some way connected to death or disaster (or at least something in one way or another "macabre"). This can come in various forms (see categories of dark tourism), but that connection seems to be the bottom line. The connection can be very direct, as in the mausoleums of great communist leaders whose actual dead bodies are on public display (e.g. Lenin's in Moscow). Or it can be rather indirect, as at sites of volcanic destruction (e.g. Iceland or Hawaii) which may not have involved any actual deaths – just the fact that it could have may be enough to give the sites a 'dark appeal'