vatican museum

Pallas Athena/Minerva with her aegis.  Roman mosaic (3rd cent. CE), surrounded by a modern (18th century) mosaic depicting celestial bodies and geometrical patterns.  Now in the Museo Pio-Clementino, Vatican City.

Of all the classical manifestations of the primordial Great
Goddess who called Hermes into the world as the prototype of the
secret lover, Hecate is the most Hermetic. As a messenger
(angelos) she must be winged, just like her purely celestial
Doppelgängerin, Iris. Like Hermes, Hecate guides souls; and at
crossroads, represented by the Hecataia which were built up on
three-cornered pillars, she appears just as out of place in the
classical world as do the four-cornered roadside Herms. At every
new moon she there received cakes and smoked offerings, as did
Hermes. With Hermes she guards the gates and with him, too,
brings wealth and good fortune to barns.
Karl Kerenyi “Hermes Guide of Souls”

A detail of a 3rd century CE Roman statue of Hecate (or Hekate), goddess of the Moon. As here, she is often depicted having three heads and bodies. (Vatican Museums, Rome).

Imagine all the artists from hundreds of years ago standing on scaffolding to create this 100% painted ceiling. The artwork is 2D, but it looks three-dimensional. 

Vatican Museums, Vatican City