As the name suggests, the Bubbleator was a giant bubble used as a hydraulic elevator. Built specifically for the fair, the giant machine was housed in the Washington State Coliseum -- now known as Key Arena.
For nearly two decades it was a fixture at the Center House, moving hundreds of thousands of people up and down two floors.
For the Bubbleator's current owner, Gene Achziger, the story of how the bubble ended up as a greenhouse in his yard is a quirky one.
In the 80s, Achziger went looking for the Bubbleator, curious about what happened to it after the World's Fair.
He says a contractor donated it to the Children's Orthopedic Hospital, but they didn't know what to do with it and, by 1984, it was stuck in a warehouse in South Lake Union.
"It was all in a pile, just one giant heap," Achziger said.
He said the warehouse owner offered to sell it to him.
"I made an offer, and he said no it was too low," he said. "Went back to work, we did the story, and he called me up and he said, 'Double your offer and you can have it.'"
So, for $1,000, Achziger bought the Bubbleator at a fraction of its original $63,000 price tag. He put the dismembered machine on a flatbed truck and brought it to his house in Redondo to begin the painstaking process of putting it back together.
"The thing is it's machine drilled, so every panel has to go in exactly the right place," he said. "Well, there were no instructions on how to do it."
Now back in its original form, the Bubbleator stands just over 19-feet wide and weighs more than 3,000 pounds.
Achziger said it took him three months and plenty of help to get the machine back together.
"I would have to recruit neighbors to come over, and we would have to like take a panel, and move it into place, and then check to see whether or not that was the right position for it to be," he said.
The Bubbleator is now a prime-time greenhouse. But, more than that, it's a connection to the past for Achziger and his neighbors.
"One of the neighbors across the street, their daughter was a student at Western (Washington) and she came home," he said. "She has pulled up in her car, slammed on the brakes, jumped out and she's out there jumping up and down screaming, 'It's the Bubbleator, it's the Bubbleator."
The sixth-month celebration for the World's Fair kicks off on Saturday at 10:30 p.m.