Outside the centre of Sofia, there is a unique monument dedicated to children all over the world. It is 37 metres tall.
Wikipedia https://bg.wikipedia.org/wiki/Камбаните
More information http://www.nukk.org/projects/the_bells_monument/en/present.html
Адрес Bulgaria
Координаты 42°37'6.363" N 23°22'45.451" E