It is a compact piece of stone that was used as a tool for determining geographical locations in the city of Karlovac, and the numbers written on it represent the distance from Karlovac to some cities such as Zagreb, Rijeka, Varazin and even Vienna. The teacher shows these distances in so-called "German miles" (one mile equals 7.532 km), and this also shows that it was built before 1780, when the Austro-Hungarian Empire adopted the metric system. This monument is considered a symbol of the economic development of Croatia at that time.