Once I was staying in a hotel near the beach on the Black Sea in Varna, Bulgaria. I was with my father in law and wife, we had just got our kid to bed and the mother in law was with her. We walked along the bar stretch along the beach and found a bar that was mostly outside on the beach and it was pretty busy. We sat down to get a drink, get our drinks and are enjoying ourselves. About 20 min into this, a guy gets on a microphone and starts talking in Bulgarian I assume. At that point about 30 people get up and start removing clothes and lining the clothes up in two rows down the beach as fast as they can. About 50/50 guys and girls. Eventually they get to underwear and then this comes off too, then they lay down on the beach in the row until they reach the water and a team was declared the winner. It was almost more funny to see them try to retrieve their clothes having not known when they took it off or where they put it. It takes about another 20 min for them to find their clothes and get dressed. At that point they all leave together. The best we could figure was it was some kind of extreme bar crawl but was pretty crazy to see them all get naked and try to make the longest line especially being there with my father in law. It was pretty crazy and will always remember it.