前苏联有三个，两个在俄联邦（即和，一个在乌克兰（即）。这三个城市都有悠久的历史，在地理版图上三者几乎呈等边三角形状，而正处于这个三角形的中央。一、位于河畔，与湖毗邻。早在十一世纪以前它就以的北方重镇著称，处于出波罗的海与北欧西欧诸国交往的要道上，商贸发达 Three in the former Soviet Union, two in the Russian Federation (ie, and one in Ukraine), have a long history of three cities, almost all of which are equilateral triangles on the geographical map, and are in the triangle Central. First, located in the river, adjacent to the lake as early as the eleventh century before it is known as the northern town, out of the Baltic Sea and the Nordic countries in Western Europe, the main points of contact, developed commerce