Zagreb Observatory – Popov Toranj (Priest’s Tower)

Popov Toranj, built around 1247, is considered the oldest surviving structure in Zagreb. Originally a property of the Archbishop of Zagreb. located within the territory of Gradec, the tower stood for centuries at the centre of disputes between the Chapter and the city authorities, eventually earning the popular name Popov turen. Severely damaged in the 1880 earthquake, the tower underwent extensive repairs in the following years, during which its masonry was reinforced with iron tie rods—still visible today. Its most significant transformation occurred in 1903, when the original tented roof was removed and a new third storey was added, complete with an arched opening and terrace to house the observatory of the Croatian Society for Natural History. Designed by architect Vjekoslav Heinzel, the observatory opened on 5 December 1903, founded by the Croatian Society for Natural Science. As a public institution open to young people and citizens alike, the observatory ranks among the oldest and most successful European observatories.