Where is the world’s oldest underground railway?

The first city to build an underground railway was London. Once the route was planned, a great trench was cut along the streets, the railway tracks were laid and the trench was covered over again, to restore the road and create a railway tunnel underneath. This method of tunnel making is called cut and cover.
The original route of the London Underground was nearly four miles long and ran from Paddington Station to Farringdon Street in the City of London It was opened 1863. The first trains were hauled by steam engines, and the smoke in the tunnels made the journey very unpleasant. But as the world’s first underground railway it was a cause of great excitement and regularly carried 30,000 passengers a day.
Further sections of steam operated underground railway soon followed. Then in 1890 the first really deep-tunnel or ‘tube’ railway was built in London. For this new tube railway, electric locomotives were built. The first trains they hauled had no windows, because windows were thought to be unnecessary if the train was only to travel through a tunnel deep under the ground. The train guard called out the name of each station as the train arrived at it.