The SS Great Britain spent her first eighteen months trapped in Bristol’s harbour, too wide to squeeze out of the city that built her. It was an awkward start for Isambard Kingdom Brunel’s masterpiece, launched in 1843 as the world’s largest ship and the first ocean liner to pair an iron hull with a screw propeller.

Later she ran aground off Ireland, carried gold-rush emigrants to Australia for 30 years and ended up as a coal store in the Falklands. Her rescue in 1970 was hatched over a “good dinner”, and her rotting hull was patched with Royal Navy mattresses for the voyage home.

VoiceMap’s self-guided audio tours follow the harbourside past her masts, tracing Brunel’s scheme to carry passengers from London to New York by rail and steam, and revealing the day she was towed beneath the Clifton Suspension Bridge, the only time his two great creations ever met.