A quite common sight in many European cities is a bridge where love hearts can put a lock onto its railing. Krakow has its own as well and it makes for a nice stop when heading from the old Jewish quarter towards the ghetto.
Wikipedia (Polish) https://pl.wikipedia.org/wiki/K%C5%82adka_Ojca_Bernatka
Address (Unnamed Road), Kraków 31, Poland
Coordinates 50°2'47.629" N 19°56'50.992" E