I took a photo of this city clock at the Zagreb main square. There are clocks like this one all over Zagreb and all of them are maintained by the same watchmaker called Lebarović. On their site you can see a gallery of lots of public clocks that they maintain all over Croatia. There is a specific Zagreb custom connected with this particular clock on the Zagreb main square - it is a place where people meet. So, if you want to meet with someone in the city center, you'll just say: Let's meet under the clock!