That's a Ukrainian tune called Фриендс оф тхе Моунтаин Дулкимер.
No not at all. I'm joking. It sounds Celtic to me, too, but Ken may be right that there are pieces of a couple of tunes there. Part of it is a melody I know, and I may pop in in the middle of the night when I remember it's name. But I don't recognize that descending ending/turnaround.
By the way, that Cyrillic up above just says Friends of the Mountain Dulcimer.
BWAHAHAHAHAHA! I thought it translated as Amigos del dulcimer de la montaña hee hee!