Smooth balls of ice rolled ashore on a beach in Finland and piled up like a gigantic clutch of turtles’ eggs. Although fairly rare, these ice eggs form similarly to sea glass or rounded stones that wash up on the beach, said BBC Weather expert George Goodfellow. Chunks of ice break off from larger ice sheets in the sea and either taxi to shore on the incoming tide or get pushed in by gusts of wind at the water’s surface, he explained. Waves buffet the ice chunks as they travel, slowly eroding their jagged edges into smooth curves. Seawater sticks and freezes to the forming eggs, causing them to grow like snowballs do as they roll across the ground. Once the ice chunks reach shore, pounding waves tend to buff out any lingering kinks on their surfaces, leaving behind nothing but sleek and shiny “eggs” for curious tourists to happen upon.