Earlier this summer Argentinian artist Leandro Erlich devised an architectural optical illusion installation in London that allowed visitors to cartwheel across the façade of a Victorian house. Turns out that was just the tip of the proverbial iceberg, and he's got a whole oeuvre of intriguing illusions on his résumé, like this fragment of a building he suspended 33 feet above the ground at France's "A Journey to Nantes" art event in 2012. According to the installation's description, Erlich means to "question and problematize our perception of reality. Faithfully re-enacting domestic interiors or walkways, they suddenly spark a moment of doubt: through the subtle play of mirrors, false bottoms, or trompe-l'œil's, spaces are deconstructed and multiplied." Yes, it's obviously not made to be inhabited, but it's kind of hard to not think that, in most major cities, this could probably be listed for some exorbitant sum and touted as a "one-bedroom walk-up with a dramatic entry and lots of wow factor."