Variations: Ivana Kupala, Ivan Kupla, Kupalle, Kupaly, with the idea that the original pagan solstice was kupalle or some variant, with a later Christian grafting, a la Christmas/Saturnalia or calling the Pantheon a Catholic church, of a saint named Ivan onto the solstice-base...unfortunately lots of search terms and few good pictures, though I now have the explanation for the mystery headgear of some nighttime skinnydippers I posted a while back:

Yeah, I thought I recognized those (I DO remember most of the things you post).

but you are right, not much under those search terms.

thanks,

Klondike

Some Khan Altay / Кхан Алтай
 

pennywiseguy2

Russians strip on stage
 

maybe someone to reads Russina can read the sign and can figure what type of event this is from?

Russians strip on stage
 

part II

The event in Moscow beer factory.

"Space of Joy" fest

Next+Kazantip+bonus

____

Try Russian: "Иван Купала", "ночь Ивана Купалы". But, yes, there is not much interesting stuff anyway.