A lot of the so-called mysteries really aren't that mysterious, for example:
The undressed state of the hikers can be easily explained by a phenomenon which occurs when someone suffers from extreme hypothermia, known as paradoxical undressing, which occurs in 20-50% of all hypothermia deaths. The claims of radiation and the quotes of Soviet investigators don't exist in the original official documents. The rest of the observations can be explained through either an avalanche or scavengers such as wolves.
Similar things have occured in
Guatemala city, known as piping pseudokarst, which occur when volcanic ashes are eroded, through water or permafrost. They are quite well known in Siberia for example.
http://www.caves.org/pub/journal/JCKS/PDF/v69/cave-69-01-103.pdf
Cthulhu?
There's no known ship by that name nor any mention of the incident in the Lloyd's shipping register, used for insuring merchant ships, nor is there any ship by that name registered in the Netherlands, there doesn't seem to be any source indicating the existence of the ship.