What exactly is hidden in the pyramids?

[TobinL]

as pointed out by @ChuckV
It is the laboratory of Dr. Funkenstein!

Doctor Who's real name is d³∑x²

Yeah, well be sure and dig on this, too… Funk upon a time In the days of the Funkapus The concept of specially-designed Afronauts Capable of funkatizing galaxies Was first laid on man-child But was later repossessed And placed among the secrets of the pyramids Until a more positive attitude Towards this most sacred phenomenon, Clone Funk, Could be acquired

[wrecksdart]

That depends on your definition of hidden.