One of the most interesting sights of Vyborg is the Round Tower (Pyöreä torni, Runda tornet). It is located on the Market Square, where in the 16th century there was a wall with towers surrounding the city with a stone ring. The structure miraculously survived fires, wars, and destruction; it is a stone artillery tower of the rondel type, one of two preserved combat towers of the medieval Vyborg fortress. It was built between 1547 and 1550 by the engineer-fortifier Hann (Hans) Bergen. In the 1470s, the city, which had grown on the peninsula east of Vyborg Castle, was enclosed by a stone wall about 2 km long. The wall included 10 towers. One of the five towers on the eastern front protected the so-called Cattle Gate, hence its name Karyaportti (Cattle Gate). However, improvements in artillery and fortress warfare required strengthening the defense — by order of Gustav Vasa, a squat, powerful rondel tower (a type characteristic of late Gothic fortifications) was built, protruding 17 meters in front of the city wall to conduct enfilade artillery fire (it was planned to have two such towers). The tower’s plan was somewhat egg-shaped, with a diameter of about 21 meters and wall thickness at the base of about 4 meters on the eastern side and about 3 meters on the western side. The Round Tower was connected to the Cattle Gate gallery by two stone walls 2–2.5 meters thick with an internal passage (such a defensive structure is called a barbican).

In 1564, by order of King Eric XIV, construction began on a bastion fortress that encompassed new city districts lying to the east. Due to the unusual appearance of the angular bastions, the fortress was nicknamed the Horned Fortress. The Round Tower was included in the new defensive system — the curtain wall approached it from the side of the present-day market.

One of the bloodiest stories of Vyborg is connected with the Round Tower. In 1599, a fierce struggle for the throne unfolded in Sweden between the officially crowned ruler Sigismund and his uncle Duke Charles. Charles had enormous influence in the army and turned his claims to the throne into a real war. Sigismund was forced to flee to Poland, and Charles began persecuting his supporters. In Vyborg, as in other Swedish castles, bloody reprisals were carried out. Charles’s soldiers publicly beheaded the most influential townspeople, including the castle commandant Arvid Tavast. The heads of the executed were brought to the Round Tower and displayed on iron spikes for public viewing. This event, which took place on September 30, 1599, became known as the “Vyborg Massacre.”

In 1609, the “Vyborg Treaty” was signed in this tower by representatives of King Charles IX and Tsar Vasily Shuisky regarding military assistance that Sweden pledged to provide Russia in the war against the Poles (in exchange for the Korela fortress).

But times change, and the once formidable fortification had to change its role. Our heroine has served in many capacities. At different times, it housed an arsenal, various warehouses, and even a “sheep prison.” Townspeople often left livestock directly on the grassy earthen ramparts, which was strictly forbidden. The “offending” sheep were locked by the city guard in the gallery between the towers until the negligent owner paid a fine.

After Vyborg was captured by the Russian army in 1710, the tower, called the Petersburg Tower, found itself behind the lines and gradually lost its military significance. It began to be used as an arsenal; in addition, a toll was collected there from visitors.

When in 1861 the fortress walls and bastions were demolished according to a new urban plan, the Round Tower ended up on the edge of the newly formed Market Square. At various times, the tower was used as a warehouse, an explosives storage, and even a prison. Officially, the tower was called the Peter’s Tower, but it also became known by another name, “Fat Catherine.” It was repeatedly proposed to be demolished, but in 1922, thanks to the efforts of Vyborg’s then chief architect Uno Ulberg, the building was adapted for public use, including for meetings of the Technical Club, where Vyborg’s technical intelligentsia gathered. On the first floor, a lobby and service rooms were arranged; on the second floor, the Silver Hall for meetings, a library, and a small Renaissance Hall. On the third floor, the large Renaissance Hall was opened — the main hall of the “Round Tower” restaurant, decorated with paintings on historical themes, from the founding of the castle to the city’s capture in 1710 by Peter I, with descriptions of the scenes in Finnish, Swedish, and Latin. The series of scenes ended with the winged Latin phrase “Per aspera ad astra” (“Through hardships to the stars”).

During the Great Patriotic War, the Finns organized a kind of field kitchen in the Round Tower for those restoring the city after bombings. Sometimes the Vyborg municipality also held meetings in the tower.

In the postwar period, the Soviet authorities arranged a pharmacy warehouse in the tower. Later, the Round Tower was transferred to the city public catering trust, and after restoration, including the recreation of the Renaissance Hall wall paintings supplemented with descriptions in Russian.

Sources:

http://vyborg-info.ru/places/146-all-attractions/64-2009-02-11-18-10-55

https://ru.advisor.travel/poi/Kruglaya-bashnya-Vyborg-18770

https://ru.wikipedia.org/wiki/Круглая_башня_(Выборг)