Open House London 2016: A free pass to snoop around the city's most exclusive locations

(CNN)Politics in Britain has, in recent months, looked something like a game of musical chairs. Careers have been made and broken, offices resigned from and assumed.

One man who's profited from the tumult is former Mayor of London Boris Johnson -- he's walked from Norman Foster's City Hall to the Italianate chambers of the Foreign and Commonwealth Office.
And now you can, too -- if only for a weekend.
    On September 17 and 18, Open House London gives the public a free pass to look around some of the city's most exclusive locations -- such as Johnson's new digs -- many of which are hidden behind lock and key for 363 days a year.
    Now in its 24th year, the event boasts a glut of new acquisitions. Of the 750 venues, 140 have never had such public access before. For instance, you can scale the Leadenhall Building (aka The Cheesegrater) designed by Richard Rogers, and visit Rogers' House, which the British architect built for his parents in Wimbledon.
    Five winners of the Stirling Prize -- the UK's most prestigious architectural accolade -- are also on show, but it's private homes, such as Folds by Bureau de Change Architects, in Haringey, that set pulses racing. It's not often you get to look around a stranger's living room or take a peek in their garden, especially not those as beautiful as this.
    The Hidden House in Kensington features a light-up dance floor and waterfall.
    Housing projects include self-built and zero-carbon homes, while Bedzed, in Sutton, and Walter Segal's buildings, in Lewisham, show that there's more than one way to skin a cat.
    If daylight isn't your thing, you could always delve beneath the city into the labyrinth of Crossrail -- a project with a budget in excess of $20 billion. (Have a look before it opens and the commuters descend.)
    "From a Battle of Britain Bunker to the Argentine Ambassador's residence, Open House weekend gives Londoners the chance to explore the city's great buildings and places that are usually off-limits," says Open House director Rory Olcayto.
    "Whether its super-contemporary private homes, iconic skyscrapers or hidden gems like the Crystal Palace subway, very little is off limits during these two days."
    There's a lot of ground to cover, but if you don't manage to visit Boris' past and present haunts, you could always go one better than him: walk through the door of 10 Downing Street.
    Open House London 2016 takes place on September 17 and 18.