What's pictured above might recall one of the great Byzantine cisterns in Istanbul, but its location is rather less exotic - Honor Oak in south London. It's one of two huge underground reservoirs there. Much enlarged, the image has great impact in a London Architecture Biennale show called SUB urban - a collaboration between photographer Alan Williams and A-EM Architects.
As the title suggests, Williams' subject is what lies beneath the capital's streets: vaults, columbariums, cabling, surveillance centres, wine bars. The basement of Lobb's shoe shop, its shelves crammed with shoe lasts, could be an installation in a Holocaust museum. And A-EM has found the ideal place to exhibit Williams' pictures - the warren-like basement of a former brewery in Clerkenwell, whose dim vaulted chambers and alcoves are kin to the catacombs off the Appian Way. The show runs from 16-25 June at 187-211 St John Street, London EC1 ( www. sub-urbancity. com).
In contrast to Williams' subterranean agenda, the Architecture Foundation's new exhibition, Airspace, asks 'What Skyline Does London Want?' With digital images by Cityscape simulating the treats or horrors in store, it's at 350 Euston Road, London NW1, until 14 July. As well as a website which presents -ve possible London skylines, and invites you to vote for your favourite ( www. airspaceweb. com), there are several evening events, including one on 29 June featuring 'passionate advocates' for three different scenarios. And on 23 June at 19.30, Rem Koolhaas, Adam Caruso, Foreign Of- ce Architects and Lee Polisano will debate the subject at the Barbican Centre ( www. barbican. org. uk).
That is a probable highlight of the London Architecture Biennale, which begins tomorrow and continues until 25 June. If your idea of the perfect breakfast is one spent listening to Janet Street-Porter or Alain de Botton, then your luck's in; alternatively there's a lecture by Peter Ackroyd - who was a big draw at the last biennale - at Tate Modern on 22 June. Exhibitions include one at the Smithfield Gallery on Zaha Hadid's London projects. All programme details are on the website ( www. londonbiennale. org. uk).
For forthcoming events visit www. ajplus. co. uk/diary