The most beautiful boulevard in the world is home not only to many of Vienna's best-known sights, such as the Imperial Palace, the Kunsthistorisches Museum and the Natural History Museum, the Vienna State Opera and Parliament. Magnificent palaces, extensive parks and important monuments also line the "display window" of the former Danube monarchy.
Vienna's Ringstrasse is 5.3 kilometers long. Long enough to provide space for numerous monumental buildings, which were built during the period of Historicism in the 1860s to 1890s. Today, the buildings that stand there – from the Vienna State Opera to the Museum of Fine Arts – are among the most important sights in the city of Vienna.
Nobles and rich citizens hurried to build pompous palaces along this magnificent boulevard. Many of these former private homes can still be admired today (mostly, however, only from the outside). The style in which the buildings were built went down in history as the Ringstrasse style (a type of Historicism). It is marked by a pluralism of styles: numerous architectural forms of previous epochs were imitated.
https://www.wien.info/en/sightseeing/ringstrasse