Röda skogen is the forest area closest to the nuclear power plant.
The name comes from the reddish color the pines received when they had died from the high radiation levels after the 1986 accident.
Today, the banned zone is one of the most radioactively contaminated sites in the world.
Therefore, it is only allowed to stay in the area for a limited number of hours a day.
Some Russian soldiers have been staying there for over a month, according to information to the news agency AP.