New unexplained holes have appeared in Siberia following the mystery over a giant crater on the Yamal Peninsula.
A second is in the same permafrost region of northern Russia, and a third on the Taymyr Peninsula, to the east, in Kransoyark region. Both were spotted by reindeer herders who almost fell in.
The original hole received worldwide attention after being identified by helicopter pilots some 20 miles (32km) from a huge gas extraction plant at Bovanenkov.
The gas extraction plant connection is interesting. To read more, click here.