abstract architectural backdrop background barrier brick brick-wall bricks brickwork cement coloring colors colouring colours constructed corner corner-wall exterior external firm fixed linear lines merger merging mixed mortar perspective perspectives repaired secure security smooth solid standard strength strong style surface surfaced surfaces texture textured textures variation varied various wall wallpaper animal art artwork ball beach branch branching bubble crab closeup coast construction crab crustacea details dotilla dotillidae environment feed food foraging grain hole intelligence life little macro marble marbles marine memory nature network ocean pattern process art radial sand sandy Scopimera sea shore sphere spheres structure symmetry wildlife basic color colored colour coloured covered covering green Rendered rendering traditional-brick-wall walled well-built angles appearance backgrounds blocks contrast contrasts cracks discoloration fitted foundation foundational growth height high large limestone moss old plants retaining retaining-wall stone stones stonework variations variety contours lichen rock rock-face rockface rough active activities adventure adventure-playground bolders boulders carved carvings children children’s-playground climbing cover crawling cubby dark entrance equipment exit families fun hiding hut kids leisure light lookout park playground playing rocks safety shade shaded shadows shady shelter suburban sunlight sunshine trees tunnel uneven woodwork windows