Wow, amazing!
They remind me of the Moeraki boulders, huge ball curved rocks, down in New Zealand.
These were shaped by the waves during millions of years, are about 2 meters wide and were believed to be giants eggs in the local legends.
More info : https://en.m.wikipedia.org/wiki/Moeraki_Boulders
RE: Bizarre Natural Phenomena Vol. 60 - When The Seas Decide To Make Snowballs (Natural Snowballs Form In Siberia)