Mystery metal boxes

 When we visit the chapel on left bank - 2nd Branch - we noticed these metal lids on a box in the ground...they are in between older apartment buildings and we didn't know what they were - vents for the underground hot water pipes?  graves? 

 Some were propped open - some were not - Elder Heiselbetz wondered if they were 50-60's bomb shelters?

 The trees at the back of the picture have grown up around an old house -fallen down.

close up of our mystery boxes - I printed a picture and took it to the office last week and one of the Russian brothers who works there and speaks a little English told me ... ' they are - where people put their potatoes, carrots ... So they are root cellars!   Mystery solved!!  People have land out side of the city - some of the branches had lower attendance in the summer when people were out working their land ... then they bring their harvest back to town and store it in these root cellars, at least they used to.  Not many looked currently used - but maybe.