<http://schema.org/keywords>
"asia, yemen, sanaa, capital, city, architecture, view, travel, ancient, building, Architecture, Cityscape, Exterior, Nobody, Old Town, Outdoors, Urban Scene, View From Above"^^<http://www.w3.org/2001/XMLSchema#string>
<https://marketplace.500px.com/photos/21839841/sanaa-view-by-csilla-zelko>