Designed by Theophil Hansen, the same architect who created the plans for the Österreichisches Parlament (Austrian parliament) next door, Palais Epstein houses Austrian national parliament administrative offices and the glass atrium rises an impressive four floors. The only way to see inside is by taking a free one-hour guided tour in English and German through its hallowed halls and visit its bel étage (1st-floor) rooms. Tour times can vary.
Hansen based the Spielzimmer (play room) on detail in Santa Maria dei Miracoli in Venice, giving it a filigree ceiling of gold lacework and circular frescoes.