The Austrian Post Office Savings Bank (Österreichische Postsparkasse) building dates from 1904-1906, yet it looks surprisingly modern. Its mottled façade is made of plaques of marble riveted together, with the aluminium bolt heads visible. In a highly modern approach, Otto Wagner made this into a decorative feature. He paid great attention to detail, using industrial materials in elegant decorative arrangements, down to the furnishings in the Cashiers Hall.