A nice UNESCO cover from Bosnia Mostar, with 4 stamps of 0,20 dedicated to the "Stecci Medieval Tombstone Graveyards", inscribed as a UNESCO World Heritage site since 2016.
Stećci or the medieval tombstones are the monolith stone monuments found in the regions of the present Bosnia and Herzegovina, parts of Croatia, Serbia, and Montenegro. They first appeared in the 12th century and reached their peak in the 14th and 15th century. There are three sites inscribed in Serbia, at Perućac, Rastište, and Hrta.
