Oktogon is the name of the passage in the building of the First Croatian Savings Bank, which is located in the Lower Zagreb's Town. That part of the city was mostly built in the first half of the 20th century.
Ban Jelacic Square is a traditional center of Lower Town, where all the local people meet and socialize. The entire building of the First Bank was designed by plans of the Croatian architect Josip pl. Vancasa. The interior was modeled after other European cities passages. The first Zagreb covered pedestrian crossing has a central glass dome and stained glass windows. According to the scheme in J. E. Geist's Book, the Oktogon represents a type of passage with two entrances. A shopping passage leads through the building, in the middle of which is an octagonal three storey hall with a stained glass dome. The official address of the Oktogon is Ilica 5 and it connects Petar Preradovic Square with Ilica Street. The floors of the aisle are covered with square tiles in two colours. There is a dog monument in front yard, but it is inaccessible for visitors. Ilica is one of the longest and oldest streets in Zagreb.
It is the main shopping street in the center of the city, home to banks and shops of renowned global manufacturers of clothing and footwear. It extends to Ban Jelacic Square, which represents the heart of Zagreb town and main meeting point.