In the year 1900, there was a moving sidewalk in Paris.
I did a little bit of digging and according to this old book:
"In the Moving Sidewalk there is no break. In engineers' language, it is an "endless floor" raised thirty feet above the level of the ground, ever and ever gliding along the four sides of the square
—a wooden serpent with its tail in its mouth. It is about two and a quarter miles in length. There are ten entries to it and as many exits from it, distributed over the river face, along the Champ de Mars.
It never stops for passengers; you step on or off as you do on or off a 'bus in motion,
Can you imagine never walking again? Popping to the store by jumping on a moving pavement, I know we have them in airports but imagine having a whole city like this!