This is Bunkier Linii Mołotowa, PROJEKT 8813. It sits outside my hotel and is one of a series of bunkers that guard the River San at this point
In the days of the Hitler / Stalin non-aggression pact at the start of World War II, the River San was the dividing line between Hitler’s and Stalin’s forces.
It is now a reminder of the past, and apparently even accessible by arrangement. However, I’ll have to make do with an outside view of the bunker.