The picturesque remnants of this 13th-century Gothic castle are courtesy of a major flood of the Vistula in 1532, when half the castle and part of the walls slid into the river.
The iconic features of Płock are the last vestiges of the castle, two red-brick towers: the Clock Tower (Wieża Zegarowa) and the Noblemen's Tower (Wieża Szlachecka). You'll have to gaze at them from the promenade and park, as they are not open to the public.