The Middle Palace is located behind the Small Palace on Birch Alley. This impressive building was constructed by V.I. Bazhenov between 1776 and 1778. The side facades are adorned with intricate emblems of the Russian Empire's coat of arms. The name "Middle Palace" was coined by Bazhenov himself, indicating its size, which is between the "Small" and "Large" royal palaces.

The Middle Palace stands out with its rich white stone decor, reminiscent of a carved casket. Excessive decorativeness is characteristic of Bazhenov's entire ensemble. Each angle of the palace reveals new impressions from the play of architectural forms and details. The view from the pond hill is particularly impressive, where the building resembles a backdrop for an opera performance on themes of romantic past.

In the 19th century, the palace was nicknamed the Opera House due to the two-light grand hall-gallery on the park facade. This hall, with two side ante-rooms, was likely used for social entertainment by Catherine the Second in a close circle of courtiers. Concerts, theatrical performances, and balls were held here. The high hall is adjoined by a suite of small rooms on two floors, surprising with their layout and crampedness, which is unusual for royal quarters. If the chambers of Catherine the Second's main palace were similar, it is understandable why they caused her discontent in 1785.

Bazhenov's plans for the interior decoration of the Tsaritsyn buildings are unknown. Therefore, during the restoration of the Middle Palace from 1988 to 1995, its rooms were left without colorful decorations that might have existed in the 18th century. As a result, the grand hall acquired a unique appearance, combining the elegance of the Catherine era with the austerity of monastic spaces.