Plage du Havre

What Seaglassmap found here

Le Havre's beach is a long grey shingle strand right in the city, and the glass in it has a paper trail: much of it washed out of the old Dollemard landfill on the cliffs to the north, which took the city's waste from 1945 until 1999 and has been eroding into the sea ever since. Local blogs describe the pebbles as partly made of glass, brick and concrete from that dump, rolled smooth by the Channel. Greens dominate. Work the shingle banks along the Boulevard Albert 1er. Do not go to Dollemard itself: the cliff foot is an active asbestos clean-up site with collapsing ground, and it is closed for good reason. Take the glass and leave the pebbles.