Along the perimeter of the walls, between the corner towers, there are some rectangular towers with the gates.

The walls crowned with battlements (merlons) which resemble a swallow’s tail, are from 5 to 19 meters high. The height of the towers, which had wooden tents added to them in the 17th century. With stars crowning them, varies from 28 to 71 meters. Wooden-tented towers served as observation posts. Alarm bells and clock chimes were mounted on some of them. The fortress walls were covered with wooden span roof.

At the foot of Borovitsky Hill there is the Borovitsky (or John the Baptist’s) gate-tower built in 1490 by Pietro Antonio Solario. A bridge ran from the tower to the bank of the Neglinnaya River. In 1658 it was called John the Baptist’s Tower after the church, which stood next to it. In 1488 where the Neglinnaya and Moscow Rivers meet a round tower was erected which was the named the Sviblov Tower after boyar Sviblov. A water pump supplying water to the Kremlin was installed there in 1633, so from then on it was called the Water Tower. Along the walls now turning eastwards and facing the Moscow River there are the Annunciation Tower, the Tainitsky Tower, the first and the second Nameless Towers and the Petrovsky Tower erected from 1488 to 1490. In 1487, at the Kremlin’s southeast corner, a tall round Beklemishev (Moskva River) Tower was built and named after boyar Beklemishev. Next to it stands the Tower of Sts. Constantine and Helen (or Timofeyev Tower). In 1380, Dmitry Donskoy’s regiments passed through the gate of the tower that had stood there earlier, on their way to the Kulikovo Field. In the first half of the 17th century the tsar’s tribunal held its investigations there and the tower was turned into a prison. People called it the “Torture Tower”. The Nabatny (Alarm) Tower dominates the Vasilyevsky Slope opposite St. Basil’s Cathedral.

The Kremlin’s symbol is the slender ten-storeyed Spassky (Saviour’s) Gate-Tower named in honor of the Icons of our Saviour of Smolensk and the Vernicle. In 1991, the tower’s quincentenary was marked. In the center of the southeast part of the Kremlin wall one can see the Senate Tower with the Mausoleum standing in front of it in Red Square. Then follows the St. Nicholas Tower and, opposite the Historical Museum, there is the corner Arsenal (Sobakin) Tower where a draw-well was dug out for use during sieges. Then one can see the Middle Arsenal Tower and the Trinity Tower, which is connected to the Kutafya Tower by a stone bridge. The Commandant’s and Armoury Towers are situated to the south of the Trinity Tower.

The Kremlin walls and towers were built by Russian masons under the supervision of Italian engineers and architects whose names have been retained in the descendants’ memory. They were Marco Friazin (Marco Ruffo), Pietro Antonio Solario, a hereditary architect who took part in the construction of the Milan Cathedral, and Antonio and Alevisio Friazins. Foreigners left very interesting notes about Russia. Venetian Ambassador Ambrosio Contarini was one of the first to write about the Italians working in the Kremlin in his diary of travels in 1476. He wrote about “The Master Aristotle from Bologna who was building a church in the square” and about the Kremlin castle’s topography.

The talented Russian architect and sculptor Vassily Dmitriyevich Yermolin worked in the Kremlin in the second half of the 15th century. He restored the dilapidated parts of the white-stone wall of the time of Dmitry Donoskoy between the Sviblov and Borovitsky Tower. While reconstructing the St. Frol (Spassky) Tower he chiseled two White-stone sculptures. One of them representing St. George (Moscow’s emblem) was mounted on the outside of the entrance gate in 1464. The monument has survived and is now being restored.

In 1508-1516, under Prince Vassily III, a moat (Alevisio’s moat) was dug out along the east walls with the aim of strengthening the Kremlin’s defenses on the side of Red Square where the settlements was situated. It was designed by Alevisio Friazin and was 32m wide and 12m deep. The moat was filled with water and connected the Moscow River (on the south) and the Neglinnaya River (on the south-west). The Kremlin became an island fortress reliably protected on the sides of all the gates (the moat was not evened until 1801). Wooden draw-bridges (replaced by the stone ones in the 17th century) ran over the moat towards the Spassky and St. Nicholas Gates. Trade was done on the bridges in those days.

Despite the fact that the Kremlin was a fortress and in some details resembled a medieval castle, it retained a traditional spatial composition and layout typical of an Early Russian town center. In the course of excavations, ancient roadways, basements of wooden structures, and churches with necropolises around them were discovered in the Kremlin.

The Kremlin citadel’s military defenses were being constantly improved. Their protective qualities were enhanced and their architecture changed along with the development of the siege technique. Ball-firing guns became the main means of destroying fortresses and they almost completely replaced early missile weapons. The distance between the towers was determined by the weapon range. The towers were built closer to each other on the most vulnerable south side of the fortress.

In the 17th century guns were positioned on the Kremlin towers and walls, supplies of gunpowder and arms were kept in the cellars. Strelets units guarded the gateways.

In the 1620s, a large-scale construction was resumed in the Kremlin as testified by Russian chroniclers. In the period between 1624 and 1685 tiled tent-shaped tops were added to all the towers except the St. Nicholas Tower, which made the severe image of the Kremlin fortress more picturesque. According to the famous historian I.F. Zabelin, “the building of the upper tent-shaped section of the towers did not strengthen the Kremlin’s defense but gave it some other, eternal, strength and expressed the poetry and spirit of the old pre-petrin Rus”. In the 1650s, a double-headed eagle (Russia’s state emblem) was mounted on the Spassky Tower and later on the other tallest towers of the Kremlin (St. Nicholas, Trinity and Borovitsky). The Kremlin’s importance purely as a fortress was gradually lost.

Moscow and the Kremlin suffered innumerable losses in the war with France (1812): The Water Tower, the first Nameless and the Petrovsky Tower lay in ruins, half of the Borovitsky Tower’s tent-shaped top had fallen down. The Nikolsky Tower was almost completely destroyed and the corner Arsenal Tower and the Kremlin walls were also damaged. The repair and restoration work was conducted under the supervision of O.L.Bovet in 1817 to 1822. At that time, the Alevisio’s moat was filled in. The repair and restoration work was continued in the post-revolutionary period.

Since the 1970s the latest technological achievements and scientific recommendations have been applied involving many research, design, restoration and construction organizations in this work. Preventive measures have been taken to preserve the Kremlin’s unique architectural monuments- ancient constructions were given anti-corrosion coating.

Thr Kremlin’s tower clock has always been a center of attention. It was installed here for the first time in Rus in 1404. According to written sources clocks were only installed in the Spassky, the Trinity and Tainitsky Towers. In 1624-1625, Russian masters headed by Bazhen Ogurtsov added a stone tent-shaped top to the Spassky Tower. Christopher Halloway, an English clockmaker, was invited by Tsar Mikhail Fyodorovich to install a town clock on the tower for which the tsar presented him with “a silver goblet, ten arshines of red satin, forty sables and forty martens”.

Practical implementation of this unique work was entrusted to the Russian smiths and the clockmakers Zhdan, his son Shumila and his grandson Alexei Shumilov. The clock design greatly impressed their contemporaries and was mentioned in the notes of foreigners who visited Moskovia in the 17th century. Baron Meyerberg, the ambassador of the Austrian Emperor Leopold, wrote: “There is a clock on the St. Frol Tower…next to the palace bridge. It shows the time from sunset to sunrise… it is the most splendid clock in Moscow”. Most probably, after the great fire of 1701 Peter I ordered the “old-fashioned” clock to be replaced by a new one equipped with bells and music. Time did not spare it either. The currently operating carillon was installed on the Spassky Tower in 1851-1852. It was made by the Butenop brothers. The total weight of its mechanism is about 25 tons.

The architectural monuments of the Moscow Kremlin belong by right to the highest achievements of human genius. It is a valuable fusion of inspired craftsmanship and technical perfection. Several generations of outstanding masters-architects, sculptors, engineers and painters-took part in the work and left an invaluable heritage to future generations.

Sobornaya (Cathedral) Square is an artistic, historical and layout center of the Kremlin.

The architectural ensemble of Cathedral Square has retained its original medieval aspect in which traditions of early Moscow architecture and local Russian architectural schools are successfully combined with Italian masters’ achievements.

These monuments surround the Kremlin’s main square, which witnessed all the major events in the country’s life. In old documents it was called just “a square” or “a courtyard between the cathedrals and the Kremlin Palace”. It was here that, according to tradition, the Tsars met foreign ambassadors and ceremonial processions paraded from the Cathedral of the Assumption during coronations and festive sermons. Even the cobblestone of the square was worn out along the road leading from south doors of the Cathedral of the Assumption to the Red Porch of the Kremlin Palace.

The coronation of Mikhail Fyodorvich, which took place at Cathedral Square, is vividly illustrated by miniatures in the 17th century manuscripts.

It is known that in the 18th century an iron fence surrounded Cathedral Square. In the middle of the 19th century, during the construction of the Great Kremlin Palace it was replaced by a cast-iron one, which is no longer there.

Today, as in the old days, the square is Always full of people. Numerous groups of tourists from different cities of our country and other states come to admire the unsurpassable beauty of the architectural masterpieces, which personify Russia’s history and culture.