The Spasskaya Tower, built of brick over the only entrance to the fortress in 1683, is the oldest architectural monument in Syzran. It is located on the side of the settlement and serves as the beginning of the city's main street, Soviet, which stretches from the tower to the northeast. Originally, the tower was two-tiered, with square sections on each tier that differ slightly in size. The passage through the tower is covered by a cylindrical vault.

The square sections end with a cornice supported by brackets with four and three steps. In 1755, two octagonal sections with a tent-like finish were added to them when the tower, having lost its defensive significance, was converted into the church of the Savior Not Made by Hands. The octagonal sections also differ slightly in size. The faces of the upper octagon have large arched openings that slightly rise above the cornice, giving it a gentle curve. All tiers are decorated with pilasters that slightly retreat from the corners. The base of the building ends with a half-bulwark.

Externally, the Spasskaya Tower resembles tent-like bell towers with an octagon above a cubic base. However, the transformation of a defensive structure into a church gave it unique features. The simplicity and symmetry of the forms ensured the integrity of the composition and restraint in the decoration of the facades, while the altar does not stand out in the external appearance. Over time, the tower became a symbol uniting the ideas of the heroic past of the city, which defended the borders of Russia, and the truth of the Christian faith.

In 1850, the tower, the church, and the icons within it were renovated with funds from merchants G.P. Serebryakov and B.I. Kolpachenko. At that time, a stone porch was added instead of the wooden one. Photographs from the late 19th and early 20th centuries show that the passage under the tower was bricked up. It is possible that there was a shop for selling church utensils that opened onto Bolshaya Street. Its facade had a symmetrical composition with a door and a small window above it, framed by rectangular windows in casings with triangular finishes.