A cairn is an artificial pile of stones, often in a conical form. Rock cairns are constructed
for different reasons. A carn can mark a burial site, or the summit of a mountain. It can
indicate a path, or it can be used for astronomy. It can commemorate an event, or
memorialize the dead. In areas with fantastic rock formations, such as the
Grand Canyon, tourists often construct simple cairns in reverence of
the larger counterparts. A hiker may start a cairn and
subsequent hikers that follow may add to it.