in which the real sites, all the other real sites that can be found within the culture, are simultaneously represented, contested, and inverted

Earlier I had a photograph of a lake acting as a mirror, reflecting the upside down landscape residing above it. That was a utopia, the place in the mirror that is turned upside down but reflects that which is real. However, Foucault later explains in the essay that a mirror is actually a real thing. Thus in that picture, there was also a heterotopia, an actual surface that represents, contests, and inverts the real outside of it. So, as Foucault later explains, there is a place where the heterotopia and utopia converge, a Purgatory to their Heaven and Hell, where imagination and reality intersect.