In a dump, used glass soda bottles are a toxic eyesore. But when rolled and softened by the waves, then spit out onto a shore, they become something extraordinary: colored pieces of stone.
It takes about 30 years for the ocean to break down glass into sea treasure, and not all beaches are capable of creating it, which is why a good sea glass beach is hard to find. The best options are usually near former dumping grounds, where there is consistent wave movement.
But seeking these beaches out is well worth the effort. Not only are they stunning in a completely surprising way, but they are a boon for treasure hunters. (Pro tip: Clear glass is the most common, as are brown and green. The most prized, rare glass is orange and red.)
Ready for your quest? Here are the best places in the world — from Japan to Northern California — where you'll find trash turned into extraordinary beach sea glass.