1, Seversk: The fortress is located in the valley, with an altitude of about 90-120m, surrounded by highlands. No matter which side's army occupied the city and lost its periphery, it was a passive situation of hitting the high with the low. Russian troops occupied the highlands of 200, 22 1 and 197 in the east of Sevsk. It is estimated that the battalion commander is at 22 1 highland. The Ukrainian army occupied the western 125 and 165 highlands, and the positions of the two sides were about 6-9 kilometers apart. The highlands of 142 and 137, which are located between the actual control lines of both sides, are the places where the two armies are fighting fiercely at present. After the Russian army takes control of the Seversk region, it will change the tactics of advancing north Donetsk-Lisichansk-Seversk from east to west, and attack from north to south along the T 1302 highway, with Bakhmut as the next main target.
2. Constantinople: The Battle of Constantinople is a typical fortress attack and siege warfare, and it is also one of the most shocking battles in world history. This battle led to the interruption of the main land trade routes connecting Europe and Asia, forcing Europeans to find new trade routes. In addition, the Battle of Constantinople also promoted Europeans to discover the new continent and explore the Atlantic Ocean.
3. Slavyansk: Fortress is an important transportation hub, industrial center and health resort in Ukraine. In the Russian-Ukrainian conflict, Slavyansk became the key defensive area of the Ukrainian army.