Palais Coburg was designed in 1839 by architect Karl Schleps in Neo-Classical style, and built 1840-45 by Duke Ferdinand (1785-1851) atop the Braunbastei (Brown Bastion), a part of the Vienna city defences dating to 1555. It is nicknamed the Spargelburg ("castle of asparagus") for its central portico with many freestanding columns.

Its last owner was Princess Aurelia of Saxe-Coburg and Gotha, morganatic widow of a prince, who lived there with her family. The owners sold the palace in the 1970's and today is a luxury hotel after extensive renovations.

Text Source: Wikipedia