Oranienbaum (Russian: Ораниенба́ум) is a Russian royal residence, located on the Gulf of Finland west of St. Petersburg. The Palace ensemble and the city centre are UNESCO World Heritage Sites.
Still commonly known by its post-war name of Lomonosov, the estate at Oranienbaum is the oldest of the Imperial Palaces around St. Petersburg, and also the only one not to be captured by Nazi forces during the Great Patriotic War. Founded by Prince Menshikov, Peter the Great's closest adviser, the Grand Palace is one of the most opulent examples of Petrine architecture to have survived to the present, although until very recently the palace itself has been greatly neglected. After Menshikov's death, Oranienbaum passed to the state, and was used as a hospice until, in 1743, it was presented by Empress Elizabeth to her nephew, the future Peter III. Peter made Oranienbaum his official summer residence and transformed one corner of the park, ordering the construction of a "Joke" Castle and a small citadel manned by his Holstein guards. This peculiar ensemble, called Petershtadt, was mostly demolished during Pavel's reign. Antonio Rinaldi, the Italian-born architect who also designed the Grand Palace at Gatchina and the Marble Palace in St. Petersburg, was commissioned by Peter in 1758 to build a modest stone palace next to the fortress, and this has survived.