<http://schema.org/description>
"Solo caving (and self portrait). This cave was featured in the BBC Planet Earth series. The film crew (and me) spent six 12-hour-days deep inside this cave sucking in CO2 levels of 5%...100 times the level outside."^^<http://www.w3.org/2001/XMLSchema#string>
<https://marketplace.500px.com/photos/13893101/exploring-susa-cave-thailand-by-john-spies>