Located along the northern border of the Private Garden. The main building of the large greenhouse complex on Yelagin Island, which housed a unique collection of exotic plants. The greenhouse was originally built during the time of Ilya Perfilievich Yelagin. Preserving the old stone walls, Carlo Rossi rebuilt the structure, redecorated the facades in a new style, and altered the layout to make it symmetrical. The central hall of the greenhouse building contained a collection of rare plants. Adjacent to the hall were the greenhouse itself and two two-story wings attached on the west and east sides. The eastern wing, where the heir’s living quarters were located, was called the “heir’s wing,” while the western wing was known as the “grand duke’s wing,” housing the grand dukes. These rooms were distinguished by special comfort and were furnished with mahogany furniture. The walls of the southern facade of the greenhouse building were glazed. Along the northern facade were the rooms of the chamberlain and valet, and there was also a barber shop. The decorative design of the facades featured cast-iron herms, created according to sketches by Carlo Rossi and sculpted by Pimenov, cast at the Saint Petersburg Foundry.

The interiors of the Greenhouse were painted in grisaille by Academician Medici. These rooms resembled palace interiors but were less formal.

Above each wing of the building, cast-iron canopies were installed in 1852-1853, cast according to a design by architect Martynov.

The Greenhouse building currently houses the Museum of Artistic Glass.

Sources:

https://www.citywalls.ru/house7530.html

https://elaginpark.org/central-park/dvortsovo-parkovyy-ansambl/oranzhereynyy-korpus/