There, here is my idea by the link of 'Kitten' on how to keep people away from the land buried with radioactive materials.
As for the part, I choose Eye, Ass and Tail.
First, Eye, I suggest making a scary looking board with a pair of sharp eye staring straight at the one looking at it as normally people tend to avoid sharp gazes even from images.
Next, the ass. The suggestion is put loads of droppings of carnivorous animals like tigers, lions around the compound. Even animals will avoid the land.
The third, the tail. Place a madman at the area to scare off people.