Three Bridges, London
Three Bridges, known formally as Windmill Bridge, is a three-level crossing of transportation routes in Southall, Greater London, England. Despite its name, the landmark features only two bridges—a road bridge over a canal, which is carried in an aqueduct over a railway, which is in a cutting. A road bridge spanned the canal since the early 18th century but the structure was replaced when the railway was built in 1856. The road bridge is a cast-iron arch and the aqueduct is a cast-iron trough, all supported by brick piers, abutments, and retaining walls. The crossing was designed by Isambard K

Three Bridges, known formally as Windmill Bridge, is a three-level crossing of transportation routes in Southall, Greater London, England. Despite its name, the landmark features only two bridges—a road bridge over a canal, which is carried in an aqueduct over a railway, which is in a cutting. A road bridge spanned the canal since the early 18th century but the structure was replaced when the railway was built in 1856. The road bridge is a cast-iron arch and the aqueduct is a cast-iron trough, all supported by brick piers, abutments, and retaining walls. The crossing was designed by Isambard K
Check the official site before travelling; hours and prices can change.
More bridges

Tower Bridge
The bridge people mean when they say London Bridge. Walk the high-level walkway for the glass floor.

Millennium Bridge
Foot-only suspension bridge from St Paul's to Tate Modern — the only crossing aligned on St Paul's dome.

Hammersmith Bridge
Currently pedestrian-only, Victorian wrought-iron beauty — best photographed at golden hour.
Source: wiki-list