Coordinates: 59°58′45″N 30°16′12″E / 59.9793°N 30.27°E Yelagin Palace (Елагин дворец; also Yelaginsky or Yelaginoostrovsky Dvorets) completed in 1822 is a palace in Saint Petersburg which is situated on Yelagin Island in the Neva River and served as a royal summer palace during the reign of Tsar Alexander I. Constructed on the site of an earlier mansion built during the rule of Catherine the Great, the villa was designed for Alexander's mother, Maria Fyodorovna, by the architect Carlo Rossi. The palace was destroyed during World War II but was rebuilt and currently houses a museum.
The isle to the north of the imperial Russian capital owes its name to its former proprietor, Ivan Yelagin (1725–94), a close ally of Catherine II from her early days as Grand Duchess. His Palladian villa might have been designed by Giacomo Quarenghi. Yelagin was fascinated with the idea of extracting gold from ordinary materials and retreated to the villa for his secretive research in alchemy. Count Cagliostro was summoned by Yelagin to help him in these activities, but fled the island after Yelagin's secretary had slapped him in the face.