The belfry of St. Sophia Cathedral belongs to the tower type of buildings, four-tiered.
From the original building, erected in 1699–1706, only the first and part of the second tier have survived to our time. Despite this, the architecture and decor of the bell tower are maintained in the same style, so they are perceived as a single entity. The two lower tiers are quadrangular in plan, the two upper tiers are octagonal. Above them rises a pear-shaped bath, covered with gilding and crowned with a crown with a cross.
The four architectural volumes of the tiers gradually narrow upwards and are crowned by a bathhouse, which gives the building a pyramidal composition and emphasizes its grandeur. The level of the composition is marked by cornices of a complex profile, the vertical surface of all walls is divided by flat pilasters, between which there are decorated niches. The three upper tiers are open to the outside with arches. A closed storage room is arranged above the passage on the first floor, to which a spiral staircase leads in the thickness of the wall on the northern side of the passage.