Reigate road tunnel is the oldest successful built road tunnel in the UK. It was built as part of a programme of road modernisation, to improve transport links at a time of heightened fears of a war with France. (A road tunnel was built earlier in Highgate, London but collapsed in 1812 before it was completed and converted into a cutting).
It is rumoured that because it shortened the distance by road between London and Brighton to less than 50 miles, this allowed the Prince Regent to be able to visit and enjoy Brighton, have a mistress and led to building the Brighton Pavillion.
The brick-lined tunnel opened in 1823, cutting through and under the rocky mound on which the ruins Reigate Castle was built. Until 1856 a toll applied for horses (1/2d) up to 6d for a coach. Pedestrians were free.
Subsequently mines were created on both sides. The sand was extracted to the east to create beer and wine storage vaults and mined in a more extensive network on the western side.
The road remained open to traffic until the early 1970s when it was pedestrianised.