Speaking of Chernobyl, you can go there with a tour guide for only a few hours. The most important thing is not to leave any camera or clothing article especially caps/hats on ground or flat concrete and likes; otherwise, they will pick up some tony radioactive elements.
I have a link about the American who went there as a tourist and did alot of pictures. They are truly amazing.
Sadly, Chernobyl will not be habitable for a long time.
