<http://schema.org/keywords>
"fog, clouds, towers, fall, white, france, black, serious, stairs, place, work, workplace, metropolis, foggy, defense, la, tours, esplanade, parvis, lang, escaliers, cnit"^^<http://www.w3.org/2001/XMLSchema#string>
<https://marketplace.500px.com/photos/18688775/metropolis-by-sergey-weaver>