I know two such places in the world. The first is Glass Beach (Fort Bragg, California) and the second one is this beach in Vladivostok (Russia). The inhabitants of the city call this place the Glass Bay (Steklyannaya).
This bay is located on the shore of the Ussuri Bay in the Sea of Japan. More recently, not far from this bay was a city dump – garbage simply dumped in the sea. For several decades Ceramic and glass from the dump have been carried by the sea current to this bay and in the beach accumulated in a large amount of sea glass.
In 2012, the dump was closed and recultivated and it left behind such a unique place as a glass beach. Unfortunately, while the city government have not yet appreciated the potential of the glass beach, it is rented by entrepreneurs who do not really care about preservation of this unique place. I hope that in the near future this beach will get a reserve status because of a great value for tourism industry which has growen a lot for the last 3 years. By the way, a lot of tourists who are coming to Vladivostok already have been taken along by their travel agencies to see that beach and have already fallen in love with it. Unfortunately some of visitors trying to keep glass treasure and taking bags full of glass away from the beach, while it should be strictly controlled by government.