Subways are one of the most used transit systems in the world, to the point that it’s a little hard to think about a world without them, but the first subway opened in London in 1863. There is a large amount of careful planning that goes into the construction of a subway, and a lot of it is underground. Check out the animated visual below (courtesy from our friends over at BigRentz) to see how subways are built right under our feet.
