Where can I get a freely usable geo dataset of the Great Wall of China? I would prefer a (Multi-)LineString, not something with an area but any format is ok. Vector data in any format, as long as I can somehow get it into GDAL/OGR or similar free software tools.
The only datasets I found are not publicly available and under very restrictive licenses.
OpenStreetMap has a relation (https://www.openstreetmap.org/relation/318110 (warning, huge)) but it is disconnected and incomplete.