Gottfried Semper and Karl von Hasenauer may not be household names abroad, but in the Vienna of Franz Joseph’s time they were towering architects. The duo was responsible for the soaring cupolas and sweeping staircases of two stunning mirror-image cultural institutions on the Ringstrasse. In the Kunsthistorisches (Art History) Museum, famous stairwell-roof frescoes are by Gustav Klimt, and the rich assemblage of works includes Pieter Brueghel’s Tower of Babel, Caravaggio’s David with the Head of Goliath, and works by Dürer, Raphael, and Velázquez. The sister Naturhistorisches (Natural History) Museum is home to one of Europe’s oldest pieces of art: the famous Paleolithic goddess figure known as Venus of Willendorf. There are also displays that range from insects to dinosaurs and flora and fauna collected worldwide.