One of the visitors, holding a detector monitoring bat cries, was Culture Minister Bozo Biskupic.
Biskupic recalled that the government today established a state award for the protection of natural heritage.
With 35 registered bat species, Croatia has one of the richest European bat populations. There are 45 registered bat species in Europe, many of which are endangered and facing extinction.
An expert on bats, Nikola Tvrtkovic, said that the number of bats in Zagreb had decreased due to the spraying of mosquitos, which are eaten by bats, but that the bat population in Zagreb was slowly recovering.
The organisers of the event called on the public to visit on Saturday the Veternica cave on Mt. Medvednica overlooking Zagreb, which is the only bat habitat in Croatia that is systematically taken care of.