In 1921, the Uhren Museum opened in the Hafenhaus, one of Vienna's oldest structures, exhibiting a monumental selection of 21,200 clocks and watches from the 15th century up to a 1992 computer clock, with 700 of them on display at any given time. A mesmerizing display of Biedermeier and belle époque pieces will have visitors in awe, and the stillness of the museum is broken by the hourly chimes.