I feel like you are still caught up with the category of the thing. @shritwod sums up well how I understand the clarifications around this. Replace “boundary markers” with any sign, placemarker, or object.
Sure, you can argue that the sign is {insert category}, it still isn’t apparent whether what your POI is and how does it relate to being a great place for exercise, socialization, and exploration.
- A nature sign that includes things to read is pretty apparent that it relates well toward exploration. To the point that it can be considered intrinsically eligible. A tag with just the scientific name without further context, less so.
- Survey markers are boundary markers too, the story it can tell gives a lean toward if it is eligible or not.
- Artful signs can be a standalone eligible POI as well
- Signs or focal points are ok placemarkers if it is apparent what outdoor recreation can be done within what it represents
This specific nature sign marking the boundary of a reserve, what can we gleam from that? Maybe it is not apparent whether this is a reserve to leave nature alone and thrive or is it interactive for explorers. Point out what interactions is done there wrt the eligibility criteria.