The Altar is a feminine constellation, seen from the Mediterranean latitudes close to the horizon. When one died, one stood on the boarder of the sky awaiting to become a star.

However, through erroneous  mis-interruption, scriptures completely missed the point "I saw under the Altar the souls of them that were slain for the word of god". (Revelation 6:9) When in fact, it was the Pagan Altar that was modeled on the maternal hearth, as the Altar symbolised the Mother; the earth's regenerative womb.

So there was little point in burying saints there!

As a note of interest; when the congregation sit in the pews facing the alter in church, worshiping the all mighty power that shall rise again bringing light and life to all...they are always facing east, yes east, as that is where the sun will rise again bringing light and all!