About that time the Toltecs came out of the North and took possession of the valley where the City of Mexico now is.

They were industrious, peaceful and skilled in many of the arts.

They kept their records in hieroglyphics.
"They had a year made up of eighteen months of twenty days each, the other five and a fraction being chucked into the calendar any old way.
They knew about the stars and eclipses, and built great cities.
"When they build their temples, it is said, they found ruins of other temples beneath them.

And the ones who built the temples, the ruins of which the Toltecs found, doubtless found ruins of temples when they began to dig.

It is wonderful.