“Umbilical stones” or portakars (պորտաքար) are ritual stones in Armenia, associated with the cult of the goddess of fertility and motherhood (most likely, Anahit).
Probably, the well-known myth about the birth of Mithra (in the Armenian mythology – Mher) from stone also influenced the formation of traditions about the portakars. In this regard, the portakars were also considered the gateway to the other world.
In a pre-Christian ritual ceremony, women who wanted to become pregnant laid down or pressed themselves to the portakars with their stomachs, which promoted pregnancy. A part of the ceremony was lighting candles and the fumigation of a portakar with incense.
If such a rite resulted in the birth of a child, a sacral sign-mark was put on the portakar. Accordingly, the more signs a portakar had, the more powerful it was considered and the more popular it was among the population.