The story behind this wacky landmark is that visitors from Venus arrived in a flying saucer and told former aerospace engineer George van Tassel of a process for cell rejuvenation involving a dome based on principles of sacred geometry. He began work on it in 1953, calling the dome at once a time machine, a rejuvenation machine and an anti-gravity device.
There's no documentation of its actually achieving any of that, but the draw today is 30-minute 'sound baths', in which docents stroke crystal bowls under the acoustically perfect dome. Many visitors report an out-of-body experience, so maybe van Tassel realized his goal after all.
