Intriguingly enough,
the Garden of Eden is noted for it's
great abundance of flora and fauna.
When flora and fauna die and are buried they form... petrochemicals. Oil, that is. Black Gold.
Now... If we were to look for the largest source of oil in the world, we'd say the Middle East, which is, curiously enough, the area in which the Garden of Eden would have existed.
Perhaps you see the connection here? If there really was a Garden of Eden, and it was denied to humans (by, for instance, burying), then what would the evidence be? Lots of oil.
That's where I think the Garden of Eden is. In your gas tank, and your plastic toy - it's all gone to oil.
(When do I think this all occured? During the Flood, of course... when else could you bury a freekin' huge garden thousands of feet under the ground?)