Proposed features/Natural arch
|Status:||Draft (under way)|
|Definition:||A rock arch naturally formed by erosion, with an opening underneath.|
For mapping natural arches and bridges. Unlike with a cave or other features, one can look through an arch from one side and see a substantial amount of ground or sky on the other. Like manmade bridges, natural arches can have a highway on top; the difference is that the actual hole is formed by erosion.
A photographer could be searching for a photogenic natural arch in a given area. A geologist might want to examine arches to study erosion.
Taginfo shows 10 instances of natural=arch and 1 of natural=bridge. The difference between a natural arch and a natural bridge is unclear, so I propose that both use this tag.