There are some kinds of prisons in the world in which prisoners are treated

There are some kinds of prisons in the world in which prisoners are treated very cruel. However, there is a prison in Iceland which allows its prisoners to go out without any guards to work every day. They work on the farms near the prison during the day, and come back to have their evening meal and to sleep every evening. Before they are allowed to go out like this, they have to promise to come back in the evening. If they donor do this, they are not let out.