A grotto, probably near Rājagaha, where, later, a vihāra, called the Kapotakondara-vihāra, was built. The grotto was at one time the residence of a large number of pigeons (kapotā), hence the name (UdA.244).
On one occasion Sāriputta, having recently shaved his head, was seated there wrapt in samādhi, and a yakkha, passing overhead with his friend to an assembly of yakkhas, yielded, despite the warning of his friend, to the temptation to give a knock on the monk's shining head. The yakkha immediately fell down and was swallowed up in the fires of hell. Sāriputta had but a slight headache after the blow, which was, it is said, heavy enough to crush an elephant (Ud.39f; Thag.vs.998f; PsA.494).
According to the Visuddhi-magga (p.380), Sāriputta entered into a trance at the very moment the blow was dealt him.