Between Richmond and the North Sea 30 bridges span the river Thames in London, they carry people across a stretch of river that is 35 miles long. These extraordinary structures connect a population of nearly 8 million and have been the making of London, Britains capital.

Millions of Londoners cross these bridges every week, most probably don’t give them a second thought but for British art historian Dan Cruickshank these bridges are much more than merely a means of transport, they can also be considered as a link from the present to the past.

Some of these bridges have vanished or been replaced but each of them is a clue to the city’s hidden history, in some ways they are that history.