Oil pipeline marker, near to Woodcote, Oxfordshire, Great Britain.
The white hydrant-type sign indicates that this is the location of an underground oil pipeline, with indication of whom to contact in the event of a problem.  Although presumably disruptive at the time there is now no evidence along the ground of any activity, nor can anything be seen on aerial photography.
<a rel="nofollow" class="external text" href="https://www.geograph.org.uk/profile/10124">Graham Horn</a>
CC BY-SA 2.0
From <a rel="nofollow" class="external text" href="https://www.geograph.org.uk/photo/591698">geograph.org.uk</a>; transferred by <a href="//commons.wikimedia.org/wiki/User:Adambro" title="User:Adambro">User:Adambro</a> using <a class="external text" href="https://tools.wmflabs.org/geograph2commons/">geograph_org2commons</a>.