One of Karl Friedrich Schinkel’s finest buildings, the Konzerthaus (1821) rose from the ashes of Carl Gotthard Langhans’ Schauspielhaus (National Theatre). Schinkel kept the surviving walls and columns and added a grand staircase leading to a columned portico. Check the website for free 30-minute tours taking place almost daily at 1pm or 3pm.
More in-depth 75-minute tours (€3, in German) are offered at 1pm on Saturday. From March to October, you can also sneak a free peek inside the lavish main concert hall between 11am and 6pm, expect on rehearsal or event days.