Random Riddle: 3-2-2015

My creator is a mystery,
One that’s set in stone.
My origins, my history,
Still totally unknown.

Tests of time I’ve had to face,
My strength and my endurance
Cause of weakness; it’s your race,
But I’m free of all life currents.

Was I a calendar, a tomb, a shrine?
We’ve all wondered it before.
We don’t know… but I’m a wonder!
I can tell you that for sure.

What am I?
 

Riddle