<http://schema.org/keywords>
"pico del teide, teide, pentax, tenerife, canary island, teneryfa, mountains, vulcan, volcano, wulkan"^^<http://www.w3.org/2001/XMLSchema#string>
<https://marketplace.500px.com/photos/19384405/pico-del-teide-by-michal-sleczek>