Sledovik

These are big stones, usually granite boulders of glacier origin, with hollows in them, that frequently bear traces of processing (seem to be artificially deepened and/or widened), and in some cases resemble foot traces, similar to those that might be left by a bare foot on a soft clay-like surface (hence the name).

In modern, Christian (or post-Christian) world the majority of these legends say that it was a foot of Christ (alternatively, Virgin Mary, or one of the Saints) that left the trace on the stone.

Rather, more probably, rain water and dew that accumulated in these hollows, was considered sacred, or blessed, and was used in some kinds of rituals.

[5] Some of these rituals are still preserved till modern days: thus in Pochaiv Lavra local Sledovik, re-interpreted as a place of epiphany of Virgin Mary, is venerated as one of the most important relics of the monastery; pilgrims are allowed to drink water that was poured in the footprint, and which thus is considered to become blessed.

[6] Those Sledovik and Cup Stones that are located in the wild, but relatively accessible, are in some cases also venerated by the local population, either in the christianized interpretation, or in "alternative", semi-pagan, style.

Sledovik Stone from Mendeleevo , Russia
An Icon from Pochaiv Lavra with Virgin Mary leaving her trace on a stone