This is only my opinion...but it just looks like threaded pipe with corner joints (not sure that's the right term) and stuck or cemented into the ground. Not sure it's anything official...could be wrong...I often am, just ask my wife.
Alex Looking for Texaco and Power Gasoline items
Please use For Sale forums to sell
Please - NO offers to Buy or Sell in this forum category
Statements such as, "I'm thinking about selling this." are considered an offer to sell.