Maybe on Oregon coastline, too? Glass Beach is a beach in MacKerricher State Park near Fort Bragg, California that is abundant in sea glass created from years of dumping garbage into an area of coastline near the northern part of the town.
Ice cave in the Skaftafell National Park in Iceland. Ice caves collapse and new ones form as each glacier grinds slowly towards the sea. Local guides can help you (without dying) find one. (Visit Skaftafell National Park in Iceland.