You can see them in this video:
http://www.tv100.ru/news/unikalnye-nahodki-v-carskom-sele-86063/Announced at the Alexander Palace yesterday, builders have discovered sections of the palace's historic past, constructed in the 19th century, and cemented over in the early 20th. During the continuing large-scale restoration of the palace's basements, workers restoring brick walls literally stumbled into them.
Two secret passageways were sealed into the wall for more than half a century. As builders dismantled the masonry, they could not believe their eyes. Two staircases were preserved, one in perfect condition, and even the wooden railing did had not rotted.
In the adjacent wall is another gem -- a toilet. On the wall, Metlaskoy tile one hundred years old still clings to the walls, but no plumbing remains. It is believed that the toilet belonged to Nicholas II himself, as the stairs lead to his private apartments.
The other Imperial mystery was waiting for restorers literally around the corner. There, a servants' tunnel has miraculously survived under a layer of concrete.
The tunnel, according to correspondent Anastasia Glebova appears to have been an underpass connecting the Alexander Palace kitchens to the main palace constructed in the 19th century by the architect Danini. After World War 2, the tunnels were concreted over.
While the restorers knew Danini's architectural plans from the late 19th century, in which he rebuilt sections of the the Alexander Palace for Nicholas II, they were unaware that In Soviet times, these stairs - and the underpass were bricked over.
The military occupied the building for years, and because cement was scarce and of poor quality, it was easy to see where later work had been done. To the delight of the restorers, the basement was almost untouched by civilization under the plaster and brick.
The management of the museum not decided what to do with the secret staircase and toilet - just to preserve them, or to restore them and restore access to Nicholas II's apartments as they were under the emperor. Neither is the fate of the tunnel certain - whether it is will become available to all visitors or to remain for official use only.