A random bit of road theoretically taggable as "sidewalk=both". I came across it while hiking, at least 2km from any paved road or buildings.
I say "theoretical" as I'm not confident that all apps based on #OpenStreetMap would understand "hazard=bottomless_pits_at_random_intervals", so I opted to pretend there were no sidewalks at all. It's not like they are necessary here anyway.
I suppose there is a story behind this of a property development gone horribly wrong - probably pre 2008.