At present, about 60 epigraphic monuments in the form of graffiti, bas-reliefs, chronograms are described on the walls of the Bendery fortress, made both from local building stone - limestone, and separately made, and then mounted into the walls of the fortress, slabs with bas-reliefs made of granite or marble. These epigraphic monuments contain the most valuable information for researchers, and also provide ample opportunities for identifying the building periodization of this fortification complex. The most famous of them is the so-called tarikh of Suleiman - a marble slab with a six-line inscription in Farsi, previously placed on the wall of the Gate Tower of the citadel.
In addition, a significant amount of graffiti is located on the walls of the outer bypass moat of the fortress. Three bas-reliefs and a fragment of one chronogram were recorded on the southern flank of semi-bastion No. 2 (the area of the main gate of the fortress). In the uppermost corner there is a bas-relief, made on a limestone slab, measuring 50 x 40 cm, depicting a pendulum wall clock, the hands of which point exactly at "8 o'clock", the dial consists of Arabic numerals. The pendulum is depicted in the form of a rosette, and on the sides of it there are 4 plumb lines. In the lower left corner there is a monogram in the form of two Latin letters "VK". Above the clock, in the upper field of the bas-relief, there are several numerals in Arabic inscription, which alternate with elements of a stylized floral ornament. At present, this bas-relief bears traces of destruction, especially in the upper and side parts along the edge. However, in 1819, almost all the epigraphic monuments of the fortress were redrawn by Russian officers, these drawings have survived to this day, and therefore, the damaged places of the bas-relief were completely recreated.
All researchers of the fortress came to the unequivocal conclusion that the wall clock, which appeared on the bastion after the reconstruction of the fortress by the French engineer Francois Kauffer in 1793-95, contains a cryptogram in which the carver encrypted three messages. The first message contains the top line with the number 1028 (١٠٢٨ ), the pattern between the numbers in the form of an anchor, while it is just a stylized image and does not carry any information. The second message is encrypted in the hands of the clock, the large hand of which points to the number 12 (١٢), the small one to the number 8 (٨). The third message is in Latin letters "VK".
An attempt to decipher these messages always led to different results. Odessa historian A. Krasnozhon deciphered these messages most accurately with the help of the director of the House of Friendship "Ukraine-Iran", Dr. Pakhlevan-zade.
In the upper part of the bas-relief, there is indeed a year - 1028 AH or 1619 according to the Christian calendar, and not 1208 AH. - 1793 - as it was assumed by other scientists.
Why did the engineer indicate exactly this date above the clock, and not the date of the beginning of the reconstruction of the moat? The fact is that in 1619, Turkey began preparations for a war with Poland, the plans of which included the capture of the entire Black Sea coast, as well as Ottoman fortresses along the Dniester, including Bendery. It was from this year that the outer defensive front of the fortress began to be laid in the form of an EARTH moat with bastions, which have survived to this day. The new earthen ditch covered the existing suburbs of the fortress, thus the territory of the fortress increased many times up to 67 hectares. It is this moat, its length and the presence of bastions in the moat that the Turkish traveler Evliya Celebi describes in 1657. All these fortifications stood without stone finishing until 1705, just then, until 1707, the moat and bastions became stone. Kauffer knew about this and indicated in his watch the date of laying the moat, which he did not even reconstruct, but repaired after its southwestern part was blown up by Russian troops in 1790.
The monogram "VK" can mean Turkish words written as an abbreviation in Latin transliteration: "Bender Kalesi" - Bendery fortress.
The most difficult to decipher was the message in the form of a clock hand on the dial showing 8 o'clock. This message was deciphered only when, while drawing up a plan of the fortress and carrying out measurement work, it was possible to establish that the layout of the object was made in the form of a pentagon.
When European engineers, led by Kauffer, began the reconstruction of the fortress, they immediately established that the layout of the fortress in this form resembles a pentagon inscribed in a clear circle, and the number of points for extending the radius on the circle and the location of all the external bastions of the fortress resembles a dial. Those. the image of a pendulum clock on bastion No. 2 bears the idea of French engineers about the layout of the fortress. The clock carries the idea of breaking down the fortress ensemble, where two arrows are the base radii, and all the bastions in the outer perimeter mean numbers.
As it was established during the measurement of the fortress, the nodal point of the breakdown of the outer bastion front corresponds to the southwestern, corner tower of the citadel. This is the only tower that is at an equal distance from all the corner points of the counterscarp of the moat. It is from the walls of this tower that a direct visual overview of almost all the bastions opens. It was she and the left-bank fortifications of the fortress that served as reference points for breaking up the external front in 1619, i.e. in the year, which is encrypted at the top of the pendulum clock. Thus, the number 12 on the dial corresponds to bastion No. 8, and the number 8, to bastion No. 4. In this case, the clock hands do not show hourly or calendar time, but the angle between the directions to the north and bastion No. 4 - 2400.
This only means that the European engineer, performing a topographic survey of the fortress, carried out angular measurements of the positions of the bastions from the specified corner tower of the citadel, which is what the builder of the outer bastion moat did in 1619. In this case, the clock hand has a conditional orientation to the north, and the pendulum of the clock indicates the direction to the south, i.e. to Mecca, so it is no coincidence that the end of the pendulum is made in the form of a rosette with seven petals, which symbolizes the seven names of Allah in Islam.
In addition to strengthening the outer moat of the fortress, engineer Kauffer also erected a wall along the eastern line of the fortress (now the Dniester-Avto plant), laid the Grigoriev Gates (on Russian military maps of 1819 - Dniester), built the northern and southern mouth bastions, as well as The most monumental structure in the Upper Fortress is the kronverk, a triangular stone structure in the eastern part in front of the citadel. The construction of the kronverk expanded the gun platform to protect the approaches to the fortress from the Dniester, and also made it difficult for attackers to penetrate from the Lower fortress into the Upper one.