We often hear that the zone is safe. When you visit with a guide who forbids you to enter any buildings, you don't have to worry about, of course. The ban on entering the buildings, preceded by an earlier ban on going onto the roofs,
is slowly becoming the norm for tourist groups. The regulation has been in effect for a long time, but it's being implemented more often. This comes as no surprise, if you look at the increasingly decrepit buildings.