The Tula Kremlin have the shape of a right quadrangle. The area of the Tula Kremlin is 6 hectares. Considering that the Tula Kremlin is located in a low swampy place it rests on a solid foundation, which in its turn is based on a strong piled lattice.
The walls of the Tula Kremlin has a height of 10 meters and a length of about a kilometer. In some place their width reaches 4 meters. The battlement of the Tula Kremlin is similar to that of the Moscow Kremlin.
There are 9 towers at the Tula Kremlin. There is a tower in each corner and in the middle of each wall of the Tula Kremlin. The corner towers were used for defense while the central towers had entrance gates. A tower in the northern wall of the Tula Kremlin served for storing gunpowder.
The corner towers (Spasskaya, Naugolnaya, Ivanovskaya and Nikitskaya) are round. The main entrance of the Tula Kremlin was the tower of Odoyevskiye gate, which is in the middle of the southern wall (on the side of Lenin Square). The towers in the other walls of the Tula Kremlin also have entrance gates: the tower of Water gate, the tower of Ivanovskiye gate and the tower of Pyatnitskiye gate.
The lower part of the walls and the towers of the Tula Kremlin was made of white limestone and the upper part - of oversize red brick. There were wide arches with loopholes in the walls between the towers. The gun power of the fortress was concentrated in nine outside towers, which were suitable for flank and front attacks.