By hello
Paris once had a second river. The Bièvre entered the city from the south, powered workshops and tanneries, then was progressively channelled and buried. Status: Covered through Paris, though some sections outside the city have been reopened Surface clues: Bronze markers, place names, and the broad valley around Boulevard Auguste-Blanqui and Butte-aux-Cailles Historical note: By the early 20th century, the Parisian course had effectively disappeared beneath streets and infrastructure