Visitors to natural parks often built small chedi made from stones or pebbles, a practice reminiscent  of the mani stones from Tibet, as well as of the chedi saai, sand pagodas that are built in temples as a kind of folk amusement.

The ones in the photo above are in Oub Luang National Park (fig.) in Chiang Mai, the ones in the picture on the right are in Pha Taem National Park (fig.) in Ubon Ratchathani.