Whirlpools.
Hot tubs in English gardens commonly only used three times before being forgotten,yet still being paid for.Often used under clandestine arrangement by the teenaged son of the household to entertain new girlfriends,whilst under the influence of alcohol,and under dressed.
Or
A place such as the Corrie Vreckan,a mythical maelstrom of undecided tides twisting and tossing the unwary just a few leaugues North Of the Mull of Kintyre following passage through the Crinan Canal(I can recommend this route verily*) and situate between Jura and Scarba.Not commonly seen on golf courses.
* A word of caution.The entrance lock at Lochgilphead is famed for catching out poor mariners,be alert.
Or
A proprietory washing machine manufactured by Phillips and serviced by men in vans operating under franchise.Begs the question really,I mean why buy one if it's going to need servicing?Shoddy I call that.
Or
Vortex vallacerators to be encountered frequently between ball and cup on many golf courses,otherwise known universaly as "Bad putt"
Profound though it may seem,I actually did understand the OP,and replied accordingly,but in code for the simple reason that not everyone has yet earned the right to the knowledge and I have been sworn to secrecy by the Society of Sworn Secrecies(or ... --- ... ... for short).
I am speaking out now for the public good.I wish the enigmatic among us well in breaking my diabolical code.Answers on a £20 note please.
Lizzie x