When I was a child my grandmother told me a myth of old times. I've read the myth (in a somewhat alternated version) in a book in my teenage years.
It goes like this:
A shepherd goes out to tend to his sheep, but gets tiered when the sun burns down on him. He sits in the shadow of an old oak and drinks from a spring there. Then he fells asleep. When he awakes, he does not recognize his field ("Alm", I could not find a translation for that word) anymore. Everything is grown over with shrouds, his plow is gone.
He then stands up and goes to his home, only to find it burnt down. He goes to the nearest town and everyone is dead. The plague had hit the place and all the living ones had fled, he even walked to the next city but did not meet a living person. He found a graveyard, but all the dates are in the future, so he concludes that he must have slept for at least a hundred years.
[The last part is an element that I think is special to the version the people of my grandmother]
He wanders to the top of the world and finds a woman who survived in her hut far away from people in the mountains. They have many children and their offspring still live at that place.
That offspring explains why there are people living where my grandmother comes from (a very lone valley up in the alps, "Mallnitz" is the next village today).
The story is from southern Austria, but I've read it in a book from Germany, so I assume that there are similar stories in other parts of the german/bavarian speaking area.
I remembered the story after reading the Wikipedia page Líf and Lífþrasir where a similar story is mentioned, unfortunately without link or name.