<https://www.28dayslater.co.uk/threads/penarth-slate-mine-llangollen-jan-19.117277/>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://www.28dayslater.co.uk/threads/penarth-slate-mine-llangollen-jan-19.117277/#post-1235492>