# What causes the circles on the greens at Carnoustie?

**URL:** <https://boards.straightdope.com/t/what-causes-the-circles-on-the-greens-at-carnoustie/818333>\
**Category:** The Game Room\
**Created:** [July 21, 2018, 5:47pm UTC](https://boards.straightdope.com/t/what-causes-the-circles-on-the-greens-at-carnoustie/818333 "2018-07-21T17:47:14Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![MadTheSwine](https://avatars.discourse-cdn.com/v4/letter/m/9fc29f/32.png) [@MadTheSwine](https://boards.straightdope.com/u/MadTheSwine)\
**Post date:** [July 21, 2018, 5:47pm UTC](https://boards.straightdope.com/t/what-causes-the-circles-on-the-greens-at-carnoustie/818333/1 "2018-07-21T17:47:14Z")

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Sprinkler system?

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**Author:** ![Baron\_Greenback](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/baron_greenback/32/48_2.png) [@Baron\_Greenback](https://boards.straightdope.com/u/Baron_Greenback)\
**Post date:** [July 21, 2018, 6:50pm UTC](https://boards.straightdope.com/t/what-causes-the-circles-on-the-greens-at-carnoustie/818333/2 "2018-07-21T18:50:41Z")

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Probably. Or it could be the current drought revealing the remnants of ancient settlements. It’s more likely to be the sprinklers though.

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**Author:** ![K364](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/k364/32/5_2.png) [@K364](https://boards.straightdope.com/u/K364)\
**Post date:** [July 21, 2018, 6:59pm UTC](https://boards.straightdope.com/t/what-causes-the-circles-on-the-greens-at-carnoustie/818333/3 "2018-07-21T18:59:03Z")

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I think it’s Fairy Ring: [https://en.wikipedia.org/wiki/Fairy\_ring](https://en.wikipedia.org/wiki/Fairy_ring)

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**Author:** ![Novelty\_Bobble](https://avatars.discourse-cdn.com/v4/letter/n/a3d4f5/32.png) [@Novelty\_Bobble](https://boards.straightdope.com/u/Novelty_Bobble)\
**Post date:** [July 21, 2018, 7:30pm UTC](https://boards.straightdope.com/t/what-causes-the-circles-on-the-greens-at-carnoustie/818333/4 "2018-07-21T19:30:24Z")

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I’m pretty sure they are discolouration caused by a [fungal growth](https://www.google.co.uk/search?q=grass+fungal+ring&source=lnms&tbm=isch&sa=X&ved=0ahUKEwi368bR9rDcAhXEAsAKHZnPCoYQ_AUICigB&biw=1366&bih=675).  
A fairly common phenomenon, I’ve seen loads on playing pitches and golf courses.