Tammy Winand writes:

Mani Stones are stones featuring carved mantras, most often the Chenrezig Buddha of Compassion mantra, Om Mani Padme Hum. They may be heaped together in mounds or walls, and often appear near Buddhist places of worship (temples, stupas, holy lakes and mountains, or remote places where strong spirit presences are believed to exist).

The following are some examples I have come across during my travels in Tibetan exile communities in northern India.

Mani Stone Outside the Main Temple of His Holiness the 14th Dalai Lama-McleodGanj, India

Mani Stones and Image of Guru Rinpoche near Tsuglakhang, McleodGanj…