Visited 01.12.18
I was staying in Crieff for a few (rainy) days so I visited the Knock of Crieff. The Cradle Stone is around 250 yards up the Knock Walk from the Lower Car Park, then 100 yards into the woods on the R. The OS Grid Reference is spot on. It is adjacent to a smaller boulder, also cleft in half, curiously.
There is a local belief that placing a coin in a crack in the Cradle Stone will make a wish come true. I invested 5p but I’m still waiting...
The Cradle Stone is a listed as Canmore ID 25498 (go to Links).