This is some landscape feature whose parts cannot be counted accurately, thereby revealing its occult status. This is often -- but not always -- a stone circle or similar monument.
Compare Alien Geometries
- The Ur Example is probably the Rollright Stones, to which local folklore famously attributes this property. For the record, there are currently 82 of them standing, though there were probably quite a few more originally.
- Winnie-the-Pooh has an uncountable circle of trees.
- The Doctor Who story "The Stones of Blood", filmed on location at the Rollright Stones, is about a stone circle which is called the Nine Travelers even though there aren't actually nine of them.
- Wyrd Sisters parodies this:
The stone was about the same height as a tall man, and made of a bluish tinted rock. It was considered intensely magical because, although there was only one of it, no-one had ever been able to count it; if it saw anyone looking at it speculatively, it shuffled behind them. It was the most self-effacing monolith ever discovered.
- In the Wayside School books, the school's steps work this way.
- Subverted in the prologue to Kingdom Hearts 2; it turns out that the guy just counted wrong.