bar bars color colors decay grunge letters metal natural paint painted steel rust rusty steel tube tubes typo typography urban urban decay brown build concrete construction iron oxide rebar strength redbrown shadows appearance arch arched architectural architecture barred building closed closed-doors colours construction dark distinctive doors doorstep doorway entrance exit exterior heritage historic historical lined lines locked metalwork old padlocked patterns perspectives secure secured security shut solid solid-walls steel-bars steel-gates stone stonework style textures walls wood wooden closeup hard iron scaffold scaffolding stack stacked staging stuts texture grid matrix reinforce reinforcement reinforcements sharp squares steelwire tough