Barn beam ledge with hidden storage
I modified this plan to allow for interior storage space within the shelving. Rather than nailing the front board on, I attached two lower hinges so that it functions as a drop-down panel. The front panel then secures to the top board with a centrally located screw-in hook and eye (not visible if the top of your ledge is above eye-level).
...Later discovered a similar but less toxic approach using green tea followed by steel wool dissolved in vinegar.