<http://schema.org/keywords>
"clouds, gateway, heaven, hell, new orleans, sunset, cloud, cloudscape, cloudy, colourful sky, dawn, dramatic sky, dusk, exclusive, landscape, louisiana, nature, ominous, sky, spring, storm, sun, sunlight, sunrise"^^<http://www.w3.org/2001/XMLSchema#string>
<https://marketplace.500px.com/photos/14380249/gateway-by-steven-blackmon>