The architecture of the river Thames – in pictures

London is a city divided by the Thames, but united by its bridges, which allow people to navigate the city. An exhibition at theMuseum of London Docklands displays rare archive photographs. See more photos

The Houses of Parliament and Big Ben taken from the south side of the River Thames near Westminster bridge in 1965. Photograph: Henry Grant

Echoes of atrocity: the 9/11 Memorial Museum – in pictures

The Memorial Museum, by Norwegian architects Snøhetta, has eerie echoes of a falling twin tower. Two giant, fire-charred columns rise up like fists in the entrance hall, leading visitors down to an emotional underworld of architectural salvage. More photos »

Photographs: Jeff Goldberg/Esto

Retro tech made from Lego – in pictures

Feeling nostalgic – why not try one of Chris McVeigh's Lego retro-tech models? He uses the building kits to recreate some of the 20th-century's best-loved objects, from a Polaroid camera to a NES and a classic 1980s TV set. See more »

Gherkin’s salad days over amid financial pickle for London tower

The Gherkin, voted London’s favourite tower, has been put into receivership 10 years after its completion helped transform the capital’s skyline.

The 41-storey City landmark is likely to be put up for sale shortly and is expected to attract offers of more than £550m from Middle East sovereign wealth funds and other potential buyers. Read more »

Photograph: David Sillitoe/The Guardian 

The Hoover Dam, in the Black Canyon of the Colorado river on the border between Arizona and Nevada, impounds Lake Mead, the largest reservoir in the US by volume. More from Eyewitness » 

Photograph: Joe Klamar/AFP/Getty Images

How to transform a Victorian warehouse for just £800 - in pictures

Bobby Petersen has turned an industrial loft from an abandoned graffitied shell into an airy live/work space using clever ideas and a tiny budget. Here’s how

New Banksy? Mural near GCHQ depicts agents listening in on phone box

The guerrilla graffiti artist Banksy is believed to be behind an artwork which has appeared on the side of a house in Cheltenham. More photos

Photograph: Jules Annan/Barcroft Media

Fancy a breeze-block sofa? Sarah Lucas unveils her first foray into furniture

The artist’s eponymous new collection parodies modern living, one brutal MDF settee at a time. Read more

Photograph: Sarah Lucas/Sadie Coles HQ

Royal Mail to open Mail Rail to the public – in pictures

The Post Office underground railway – Mail Rail – ran under the streets of London largely unnoticed for more than three quarters of a century. Since 2003, the electrified railway has been dormant, with just a handful of engineers to maintain it. Under new plans developed by the British Postal Museum & Archive, that could all be about to change. See more

Photos courtesy of BPMA

Stunning libraries from around the world – in pictures

'Without libraries we have no past and no future,' said Ray Bradbury. A new book celebrates the most innovative library buildings. Take a whirlwind tour with our gallery

Photos, top to bottom: Laif/Camera Press; Frank Elschner/Artur Images; Hufton and Crow/VIEW