Laputa was a floating island above Venice, Italy. In 1609, Irving Braxiatel held a gathering of aliens on Laputa in order to create the Armageddon Convention. (MA: The Empire of Glass)
Behind the scenes
Laputa was a central location in Jonathan Swift's satirical novel Gulliver's Travels. The name itself is one of Swift's jokes; la puta is Spanish for "the whore".