During a recent RS tour, I was engaged in a conversation with some locals on 3 occasions: 5-6 students in Stramberk, Czechia; 2 female best friends in Levoca, Slovakia; and 2 male best friends in Eger, Hungary. On all 3 occasions, we all enjoyed talking to each other and we took pictures. These encounters are among the most memorable experiences to me.
Looking back, there's a common thread for the encounters: (1) They happened in small towns/cities; (2) They took place in the town square; and (3) My conversation partners were all young people. Of course meaningful interactions with people we come across while traveling happen everywhere - big cities and small towns, etc., but I do find the similarity of these specific encounters interesting.
Cross cultural interactions, when happened organically, are edifying and satisfying.