OIV Tower Sljeme is the visual trademark of Medvednica Mountain and the highest point above the city of Zagreb from which a panoramic view of the entire city and the Zagreb highlands can be seen. Construction of the tower began in 1973 and lasted until 1976, when it began operating on the 50th anniversary of radio and the 20th anniversary of television.
Even from farther away, when you approach Zagreb on the motorway, the first notable sight to see is the tower topped by an antenna which juts from the mountain. It is made of reinforced concrete and iron at the highest point on Medvednica, at 1,301 meters above sea level, and its basic purpose is to provide the transmission of television and radio signals which have now been enhanced by OIV's services. Originally two television channels (TVZ1 and TVZ2) and three radio channels (Radio Zagreb 1 and 2 and Radio Sljeme) were transmitted from the OIV Tower Sljeme.
Besides this, from the very beginning the tower was the destination of many hikers, nature-lovers, skiers and other recreationists who wanted to savour the magnificent view on their visits to Medvednica.
On 16 September 1991, the Tower was struck multiple times by missiles fired by the Yugoslav Air Force, causing an interruption in broadcasting of Croatian Television, although the damage was quickly repaired. After Croatia gained its independence, the Tower was under the joint ownership of OIV and Croatian Telecom (T-HT), but in 2017 it came under the full ownership of OIV.
