The ancient entrances to the Kremlin wall are covered with hills, but you can see the brick arches. The basement level of the walls is hidden underground.

this is exactly what the gravestones looked like before the church schism in the 17th century in Russia. No crosses or any other Christian symbols. It is worth noting that these gravestones were placed in steps or thresholds in Christian churches later.

A feature of many religious buildings is metal tops. The walls of such buildings often have a metal frame inside. Considering that fire often burns inside (I keep in mind that the fire is a good ionizer), I can think about interaction with electricity from the atmosphere. Who knows, maybe the human electromagnetic field can interact with the field inside such a room.