Zagreb is the capital and largest city of Croatia. It is in the north of the country, along the Sava river, at the southern slopes of the Medvedni…Zagreb is the capital and largest city of Croatia. It is in the north of the country, along the Sava river, at the southern slopes of the Medvednica mountain. Zagreb stands near the international border between Croatia and Slovenia at an elevation of approximately 158 m above sea level. At the 2021 census, the city itself had a population of 767,131, while the population of Zagreb metropolitan area is 1,189,279.