One of the mysteries surrounding the 500,000-square foot server farm Apple (AAPL) has famously constructed in a small North Carolina town called Maiden — besides its ultimate purpose — is why it didn’t show up on Google Earth.

We knew what it looked like, thanks to the local Fox TV affiliate, a trespassing photographer and a local real estate agent who conducted a couple of video flybys that ended up on YouTube (see here).

But if you asked Google Earth or Google Maps to show you the intersection of U.S. Route 321 and Startown Road — where the data center is located —  the current satellite imagery stopped a few yards short of the construction site. West of Startown Road, there was, as recently as two weeks ago, nothing but woods and farmland and a bit of driveway that ended abruptly in the middle of a field.

After Apple’s announcement Tuesday that Steve Jobs was ready to reveal iCloud — the “upcoming cloud services offering” presumably based in Maiden, N.C. — we thought we’d give Google Maps another try.

Lo and behold, there it was: A huge, white, nondescript building with a road leading in, a road leading out, and almost no employee parking.

How was Apple able to keep Google (GOOG) from displaying this particular swath of satellite imagery — imagery provided by the USDA Farm Services Agency? That’s still a mystery.

Below: The image of the site Google Maps was delivering before the iCloud announcement.