I've only lived in Knoxville, TN, for two years, but that's long enough to build quite a bit of curiosity concerning the 266-ft Sunsphere a mere two blocks from my house. I didn't realize until finally visiting it that getting on top was something I needed to do before I left Knoxville.
After being shut down for years, the Sunsphere was re-opened on the fourth of July with limited access to the 4th floor observation deck for the masses to enjoy a view of the city from above. Without a special card, elevator access to the 5th-8th floors is completely blocked. And while the observation deck *is* pretty cool, we realized that it was, of course, just not enough. We wanted more and as it turns out, we got it.
A quick step to the side of the elevators reveals a door to the staircase bearing the warning "Emergency Exit Only - Alarm Will Sound", which we all know means "The good shit's in here". Heading through the door and up the staircase we discover that nearly all of the doors to the upper floors are unlocked, allowing anyone with enough interest to wander around inside. Our first stop was the old restaurant on the seventh floor which is supported by a full kitchen on the floor beneathe. All of these floors are under heavy renovation. Or, atleast they need to be.
The top floor features what looks like bedrooms. And they're awesome. From what I understand, the designer of the Sunsphere requested and was granted permission to live inside it upon completion and did so for quite some time.
It must be nice to wake up and check the traffic downtown without having to turn on the TV.
At the top of the staircase is a door labeled "Penthouse". But it isn't a penthouse at all. It's actually the door to the control room and, like everything else in this neglected structure, it's inexplicably unlocked. Up a couple of metal ladders and through a hatch in the roof and you're standing on the very very top of the Sunsphere!
A video from the top:
I also found this KnoxNews video that inadvertantly serves as a guide to getting to the top. Toward the end the park guide says "and obviously it's not somewhere where people can come". pwned.
Keep in mind that all the doors she went through in the video are currently unlocked while they renovate, so I suggest everyone try to get up there soon. Cheers!