Preview: Unseen Britain Unveiled, La Galleria, Royal Opera Arcade, London

Daredevil climber and photographer Mike Robertson scaled the outside of Blackpool Tower earlier this year and took pictures from nearly 158 metres up while hanging on to the steelwork.

This was his second attempt to snap the view from Blackpool Tower down to the seaside resort's North Pier and beach because it was too windy to climb during his first expedition.

However, this was not the hardest climb Robertson encountered as he moved on to another five tall landmarks across Britain to take aerial pictures, as part of Sony Alpha Unseen Britain.

The endurance needed to climb the Snowhill Plaza office block in Birmingham, which is over 70 metres high, wore him out for two days. "I climbed a vertical crack in the steel panel on the outside of the office block which was covered in shiny paint," says Robertson. "There was nowhere to rest as the windowsill ledges were too thin." At the top, he took a close-up of an adjacent office block.

The easiest ascent was the Glasgow Tower, the tallest rotating building in the world, at 127 metres, which he climbed via the lift track. He took photographs straight down the centre of its structure of a boat on the River Clyde.

For Robertson, who is used to scaling sheer rock faces, getting permission to clamber up the buildings was more difficult than it was to actually climb them. "Even when it is steep, buildings have more things to hang on to than rock faces," he says.

Nevertheless, climbing up the Park Plaza hotel to snap Leeds city centre at night and perching at the top of the 170-metre high Spinnaker Tower in strong winds to take an aerial photograph of Portsmouth harbour were no easy feats.

Robertson's most dangerous climb was up the old-fashioned Newport Transporter Bridge that carries cars across the River Usk on a gondola. His picture shows the white support cables at the west side of the bridge reaching down to nearby houses.

Today to 29 March ( www.sony.co.uk/unseenbritain)