Glass beach in Fort Bragg, California gets its name from all of the sea glass that washes up--remnants from years that the site was used as a dump site for a local glass company.
Glass isn't the only thing they dumped, and if you look around at low tide you can find spark plugs and other items that nature has cemented around over the decades.
My favorite item I found was this clockwork mechanism now embedded in rock.
@rbrown it's possible. I don't know the full history.