The south porch has almost thoroughly lost its original appearance—vaults were relayed, western and eastern walls were reconstructed, the lesenes of the cathedral’s quadrangle were cut. Its interior combines elements of several epochs. In order that visitors could easier imagine how it looked in the mid-16th century, the carved imposts were uncovered and fragments of cross vaults that have remained in the thickness of masonwork were revealed. Of interest is a portal of the 15th century, rebuilt in 1949. It was constructed in the traditions of the Old Moscow style—perspective in its form, with alternating rectangle flanges and beaded semi-columns and sheaf-like capitals. The portal is completed with a spade-shaped arch.

It appears that the south porch was partly covered with wall painting. Walls of the gallery’s chapel of Saint Nicholas were painted in 1836-1837 by A.K. Malakhov. There are scenes of the Life of St Nicholas the Wonder-Worker. Later on, the painting was more than once renewed. Today, the composition on the east wall–The Descent from the Cross– remains uncovered as well as the ornaments imitating carved décor in the upper parts of the north and south walls.