Russian scientists are baffled by big holes which have appeared in Russia's permafrost.
The Siberian Times reports that two new holes were found in the country's far north by reindeer herders, after a first giant hole was reported by the website two weeks ago.
Theories about the cause of the craters include that they were created by stray missiles, meteors, climate change or a prank.
And, of course, there is an inevitable alien origin story for the mysterious funnels.
Mikhail Lapsui, a deputy of the local duma,is quoted in The Siberian Times as saying: "I flew by helicopter to inspect this funnel on Saturday 19 July.
"Its diameter is about 15 metres. There is also ground outside, as if it was thrown as a result of an underground explosion.
"According to local residents, the hole formed on 27 September 2013. Observers give several versions.
"According to the first, initially at the place was smoking, and then there was a bright flash. In the second version, a celestial body fell there."