<http://schema.org/keywords>
"cologne, rhine, sunset, night, dark, water, river, germany, europe, travel, dome, old, historical, bridge, milky, long exposure, color, autumn, red"^^<http://www.w3.org/2001/XMLSchema#string>
<https://marketplace.500px.com/photos/17421861/sunset-in-cologne-by-thorsten-jung>