I've been looking over the GeoJSON/TopoJSON specs (as best I understand it TopoJSON is an extended GeoJSON standard which uses 'arcs' to combine features into topography rather than have each polygon as a discreet object, please set me straight if I've missed something core...)
3.1.1 states that:
Altitude or elevation MAY be included as an optional third element.
Which leads me to believe that GeoJSON should be able to cope with representing Topography (Side note - took me too long to work out topo-graphy != topo-logy, urgh greek!). So assuming we can do mountain ranges with it with contours as features...
What about caving systems? Can we do GeoJSON/TopoJSON cave maps - guess these would need to be similar altitude based contour poly slices. But I can't seem to find any good examples - which usually means this is a stupid idea for a reason I can't find.
Anyone got an insight? Or are caves beyond the scope of these JSON standards and better represented in alternative formats?