The Shukhov Rotunda is a small steel pavilion built by the engineer Vladimir Shukhov for the 1896 All-Russia Exhibition held in Nizhny Novgorod. It is the world's first hyperboloid structure — a form made entirely from straight steel bars arranged in a lattice that creates a curved, waisted shape. The pavilion originally served as a water tower for the exhibition grounds.
The rotunda has been restored and stands in a small park. To most visitors it looks like an industrial curiosity; to engineers it is a landmark in the history of structural design — the prototype of a form that Shukhov would develop over the next thirty years into radio towers, transmission pylons, and lighthouse structures across Russia and the Soviet Union. The Shukhov Radio Tower in Moscow (1919–1922) is the most famous of his creations, but the Nizhny Novgorod rotunda came first.