I stole the text from the Wikipedia
The museum is located in the business quarter of Fatih municipality in İstanbul. Its distance to Haliç (Golden Horn) is about 200 metres (660 ft). The main entrance is on Bankalar Street, a busy street to the southeast of the museum. İşbank (more formally Türkiye İş Bankası) was founded in 1924 . Although there were other banks which were established during the Ottoman Empire (pre 1922) era, İşbank was the first to be established in Republican era. One of the founders of the museum was Mustafa Kemal Atatürk the founder of Turkish Republic. The building of the museum was constructed in 1892 as the main post office. In 1917 the building was sold to a local bank and in 1927 when the local bank was bought by İşbank, the building became the İstanbul branch office of İşbank. In 1950s when other branch offices in İstanbul were opened, the branch office was renamed Yeni Camii (“New Mosque”) referring to New Mosque which is to almost adjacent to the building. The branch office was in use till 2004. In 2005 İşbank decided to establish a museum. After renewal, the museum was opened to public on 14 October 2007. In the basement, the former archive rooms are designed as a museum depot and a conference room. The deposit boxes are kept to be displayed. The cash desks in the ground floor are kept as they were and the former security rooms are redesigned as a bookshop and an information desk. The main show rooms are in the first floor.

I did not take very many pictures, but the visit was most enjoyable. Friendly staff, and a trip back in time, I am old enough to remember many of the apparatuses on display, and the general setting reminded me of offices in my youth.