One of Potsdam's newest landmarks is this replica of the 18th-century Prussian City Palace that was partly destroyed in WWII and completely removed by East German town planners in 1960. It reopened in 2014 as the new home of the Brandenburg state parliament. Of the original building, only the ornate Fortuna Portal remains; it now forms the main entrance to the compound, sections of which (including the rooftop terrace and the staircase designed by Knobelsdorff) are open to the public.
Free one-hour guided tours (in German) run Fridays from 4pm to 5pm; online registration required.
Note the two pavilions in the courtyard by German artist Florian Dombois that mimic the central dome of Sanssouci Palace.