Built in 1943, the tunnel's primary purpose was to provide shelter for civilians from frequent bombings during World War II and the Croatian War of Independence.

Nowadays, these intriguing tunnels have become tourist attraction. Temporary exhibitions and events also take place here during the year, of which the most famous was the Under City Rave party in 1993.

Zagreb has a maze of tunnels but only one is open to the public. Finding the tunnel is easy, thanks to its four entrances marked with the Zagreb coat of arms: Mesnička, Radićeva 19, Art Park 1 and 2, and Ilica Entrances.

Legends abound about secret underground passages scattered all over the city. One particularly captivating tale speaks of the great 1880 earthquake, during which many tunnels supposedly disappeared, along with precious gold artefacts from the church.

The tunnel is not recommended for people suffering from claustrophobia.