Treasure

I found the treasure
It's all mine
Left over from another time
They all forgot
But not I
I remembered where to find
The last city of mankind
For centuries humans lived
Evolved and grew
To heights anew
But alas it was to be
Time did end humanity
Still there remains
One place I know
Where the humans
Thrive and grow
This treasure though
I cannot share
The treasures burden
I must bear
The last of life
It holds the key
Thus I keep it
Close to me