My dad went to work for Phillips 66 in the panhandle of Texas when I was about 4 years old.  It had been an ammunitions production plant during WWII and was converted to a fertilizer production facility (anhydrous ammonia) afterwards.  
When I was 11 Dad was transferred to the Finley plant, Phillips 66, a fertilizer production facility.  He retired from there in the late 80's.
These tanks still stand in Finley. I think they are still being used.  In the last half-century this product has been responsible for feeding the world. 
I thought the juxtaposition of the old homestead with the tanks in the background was interesting.
 

 






















