People who didn't do their homework in advance saw that it was only magnificent. After watching it, they realized that, oh, it was the tallest building in Croatia! The online information is as follows: Zagreb Cathedral is located in Zagreb, the capital of Croatia. It is one of the most famous landmarks in the city and the tallest building in Croatia. Its spires can be seen from many places in the city. Zagreb Cathedral was built in 1093 with Gothic architectural style as a whole.