Petite Ceinture du 17e arrondissement

The Petite Ceinture of the seventeenth arrondissement is a seven-hundred-meter-long railway trench set well below the level of the surrounding streets. Once part of a thirty-two-kilometer circular rail line that looped around Paris between eighteen fifty-two and eighteen sixty-nine, it carried both freight and passengers to connect the city's major train termini. While the full line eventually fell into disuse, with passenger service ending in nineteen thirty-four, this particular segment has been reclaimed by nature.