The traditional grass mowing competition which is held annually in Kupres has been included in the UNESCO list of intangible cultural heritage. The competition is the most important social event in the area of Kupres. It takes place every year in July at a specific meadow called Strljanica, which is also the local name for the custom.

The contest involves the manual mowing of grass using a scythe and is judged by the time, effort and amount mown as cutting grass at that altitude requires strength and a special technique. The top three mowers are recognized, with the chief mower treated as a leader who ensures the successful mowing of all the fields to gather hay for the cattle.

Traditionally, only men compete while women rake the grass and prepare food for guests. Other elements linked to the competition include national costumes, the forging of scythes and the preparation of cattle for competition. All ethnic and religious groups and individuals in Kupres are free to participate.