On the eastern side of the kremlin, the Spasskaya Tower has been preserved. Its height is 24 meters, length 12 meters, and width 8 meters. The thickness of the tower walls at the bottom reaches 2.9 meters, and at the top, 1.85 meters. Inside the tower, there are five floors, one of which is underground and hidden beneath the ground. The tower was topped with a sixth tier featuring a gallery, the battlements of which, like those of the walls, resembled the shape of a swallow's tail. The height of the battlements is 2.5 meters, and their width is 1.44 meters. At the top, the tower had a four-pitched tent roof.

On the eastern side of the kremlin, the Spasskaya Tower had four "twin" towers, of which three have survived to this day: Yamskaya, Semyonovskaya, and Pogorelaya.

The name Spasskaya Tower was given due to the nearby Spaso-Preobrazhensky Monastery, which was destroyed after the abolition of the Kolomna Diocese. However, the tower has retained its name.