Sekimori-ishi

In Japanese gardens, carefully selected stones, encircled by rope or twine, are used to guard the passage. Neither barrier nor obstacle, they simply invite one not to go any further. These stones, called Sekimori-ishi (関守石) or Tome-ishi (止石), belong to one of the most subtle gestures of Japanese culture: marking the boundary without constraining, preserving the tranquility of a space through the mere presence of a sign.  

The Sekimori-ishi is inextricably linked to its braiding. Without this rope, knotted by hand according to a very ancient tradition, the stone loses its meaning.