Balcombe Viaduct West Sussex.
Built by architect John Urpeth Rastrick in 1841 it's a towering testament to the skill of early Victorian engineers and bricklayers.
What makes this viaduct special is the that the design is incredibly elegant and slim with 37 arches, 100 feet high.
It extends for 1,500 feet and comprises 11 million bricks.
It is still a working viaduct, carrying the main London to Brighton rail line.