Mansion of Jaco, Neoclassical mansion in Saint Petersburg, Russia

The Mansion of Jaco is a three-storey neoclassical apartment building from 1831 at the corner of the Square of the Arts (No. 5) and Italianskaya Street (No. 4). It has an L-shaped plan: three storeys face the street, four face the courtyard, where one-storey service wings once stood. Architect Pavel Jaco built it using Karl Rossi's approved facade designs for the square.

The plot on the corner of the square and Italian Street stayed overgrown for years after 1822, when it was given to the jewellers Franz and Johann Seguin. The architect Pavel Jaco then bought it and built the house by 1831 using Karl Rossi's approved facade designs for the square. Jaco sold it in 1836 to the mining magnate Ivan Yakovlev; in 1862 the diplomat Yakov Dashkov bought it and had Jerome Corsini rebuild it in 1862-1863, adding a photographic pavilion in 1863.

The house is named after architect Pavel Jaco, not a merchant; from the late 19th century it belonged to the bibliophile Pavel Dashkov, whose collection and "Dashkov breakfasts" drew figures such as Grand Duke Nikolai Mikhailovich and the artist Alexandre Benois. From 1911 to 1915 its courtyard basement held the cabaret Stray Dog, where Gorky, Akhmatova, Mayakovsky and Yesenin appeared. The basement and ground floor now house service businesses.

The building stands at the corner of Ploshchad Iskusstv (house 5) and Italianskaya Street (house 4), a short walk from the Mikhailovsky Theatre and Nevsky Prospekt. It is a working apartment house: only the basement and the ground floor are open as service businesses, so visitors view the facades from the square and street rather than the flats.

In the basement of the second courtyard, the cabaret Stray Dog operated from 31 December 1911 to 3 March 1915, in what had been Dashkov's wine cellar. Artists painted the rooms around the clock: Sudeykin covered walls and ceiling with birds, flowers and Harlequins, and a round table for thirteen stood under Sapunov's wooden hoop chandelier with thirteen candles hung on four chains.