"10,000 skulls of small children" killed during the Volhynia massacre? What can be seen in the photo?

Following the anniversary of the Volhynian massacre, a photograph has surfaced online purporting to show the remains of victims in a mass grave. The graphic description reads, "10,000 skulls of tiny children." However, the photograph has nothing to do with the Volhynian genocide. We explain what is known about the grave and the victims within.