Karlskirche

Fischer von Erlach's Baroque stunner on the Karlsplatz — an oval-domed church flanked by two great spiraling columns modeled on Rome's Trajan's Column, an extraordinary fusion of Roman, Greek, and Baroque ideas commissioned after a plague. The reflecting pool before it doubles the facade, and a lift inside lets you rise into the dome for a close look at the ceiling frescoes. For visitors, it's one of Vienna's most ambitious churches — theatrical, learned, and unmistakable, with the pond reflections at Karlsplatz making it a must-photograph, and the dome ascent offering a rare nose-to-nose encounter with Baroque ceiling painting.