Hidden places' open day

On July 19, the curious can explore hidden corridors beneath Federation Square, the Gothic glamour of Collins Street’s Manchester Unity building’s boardroom and the concrete catacombs of Melbourne’s first electricity substation.

via theage.com.au

Cool! This sounds brilliant. I love this kind of thing. I’ve heard about the corridors under Fed Square (they help keep the complex cool in the summer by storing cool air), and the other places sound fascinating too.