The countless stones is a motif that appears in English and Welsh folklore. It is associated with various megalithic monuments, including chambered long barrows from the Early Neolithic and the stones circles of the Late Neolithic and Early Bronze Age. The motif holds that an individual attempting to count the number of stones in the monument will be unable to do so.
The earliest textual accounts of the story date from the late sixteenth century, where it is linked to the stone circle of Stonehenge in Wiltshire. Multiple sources from the seventeenth-century also link the story to Stonehenge, although also apply it to The Hurlers in Cornwall and Long Meg and Her Daughters in Cumberland (now Cumbria).
The countless stones motif was the subject of a study by folklorist S. F. Menefee, published in the Folklore journal in 1975, and was part of Leslie Grinsell's catalogue of folkloric motifs associated with prehistoric sites in Britain.