Petite Ceinture du 17e (PC 17)

The Petite Ceinture of the seventeenth arrondissement is a segment of a once vital circular railway that girdled Paris. It started as a freight and passenger line in the nineteenth century, designed to bridge the gaps between the city's major train stations. While the network eventually became obsolete due to the rise of the Paris Metro, this specific seven-hundred-meter section now serves as a quiet, sunken garden that sits well below the level of the surrounding city streets.