Edge of the Soviet Union
The Stalin Line is the former border between the Soviet Union and the rest of Europe. Europe gave it this name, because Stalin heavily fortified the border during his reign. An enormous amount of bunkers and other military equipment can still be found scatttered along this line.
This line ran straight through Belarus. A large amount of equpment was left behind after the Soviet Union’s collapse. Belarus has built an open-air museum close to Minsk where a large amount of equipment is on display. You can visit there website here.