Beckton Alps, London, England

They appear to be open to visitors on OSM, but are in fact sealed off. Also the peak is labelled ‘natural’ but sources say it was waste from a nearby gasworks, capped with clay from when the British Library was built. Maybe this info does not need to be added, I don’t know.

The tag natural=peak is described in the wiki as “the highest point of a natural or renaturalised physical feature”. We also use natural=water for ponds and lakes which did not form naturally and natural=wood whether it is the remnant of ancient forest or planted yesterday.

The default OSM Carto map tiles unfortunately render highway=footway + foot=private or foot=no as a red dashed line, not the pale grey dashes it would use for access=private. This issue was raised a very long time ago, see Render more specific access tags i.e. bicycle, motor_vehicle etc · Issue #214 · gravitystorm/openstreetmap-carto · GitHub