Innere Stadt, AT
Designed by Friedrich von Schmidt (the architect of the Cologne Cathedral) and completed in 1883, this is the most significant neo-Gothic building in Vienna, with a 103m-high clock tower. There is a very pleasant park with two fountains in front of the building facing the Ring.
Listen to the audio guide for Wiener Rathaus Free on WIP — starts by itself when you arrive, even with the screen off