What is outside the prison door?

From the text:

But on one side of the portal, and rooted almost at the threshold, was a wild rose-bush, covered, in this month of June, with its delicate gems, which might be imagined to offer their fragrance and fragile beauty to the prisoner as he went in, and to the condemned criminal as he came forth to his doom, in token that the deep heart of Nature could pity and be kind to him.