This
page shows the dome, the oculus and the top of the bronze alter from inside the St. Peter
Basilica, in Rome. The sun light can be seen entering the Dome and the Oculus at an angle.
The oculus or the round hole is capped by a super structure, which stops the
rains from pouring in.
The darkened object below is the top of the huge bronze alter, made from material that
was originally the front doors of the Pagan temple, the Roman Pantheon, which is not far away
from the Basilica at Vatican.. The magnificent alter is the center piece of
this place of worship, perhaps its link to Pantheon also bares some symbolic
significance.
At any rate, every church or Cathedral with a dome of this type in the world, in fact, conceals a Pagan temple within it.