It's always humbling to see how the city was. Robyn Annear's City Lost & Found provides a stirling view from the pole position of atop the wrecker's ball, and the State Library has an online pictures catalogue in which you could get lost for centuries. But the Melbourne Unbuilt audio walking tour, available from the National Design Centre, shows us how the city could have been by spotlighting 13 major developments that, for one reason or another, were never realised. Told first-hand by the major works' architects and planners, it's like a trip through sliding doors into a Melbourne that never was. Sites include Federation Square, Flinders Street Station and the Arts Centre Spire.
Available: Everyday, 10am-5pm Mon-Fri; 12pm-5pm Sat-Sun. $5.

Did you hear? Someone went and dumped heaps of refuse at Federation Square. But they did it in such a splendid way (and with permission) that Green House is a destination unto itself – never mind the galleries and cafes on permanent offer. Designer Joost has created a venue made entirely of found objects (traffic signs, packing crate, straw bales and the like) and installed a full commercial kitchen, which uses produce from the rooftop garden – also made with recycled materials. It’s strangely beautiful, like dropping through the rabbit-hole into stagey surrounds that look almost normal and suspiciously attractive. It’s up until 29 January at which time it disappears completely, leaving nothing – no waste or evidence of its existence. If you ever needed an argument that living consciously can also be damn good looking, here it is.