The Anadem

Millions of years hence, when the technology and magic have long ago become one, the center of human-descended civilization will have largely forgotten the quaint backwater of its birth. Still, there  is much to recommend Old Earth as a diverting, if rustic, tourist destination.

The still-blue (or once more blue) world is garlanded with a  swarm of habitats and microworlds, aggregated in orbit over millennia. This curious and eclectic mixes of cultures and species is known as the Anadem.

Upper class youths of Earth have the custom of a the Grand Tour, a rite of passage where they visit worlds of the Anadem in the ships of alien, antigravity wood, brought to Earth in previous ages from some distant world. 

This is a Spelljammer campaign idea. Inspirational media include any number of bande dessinée from Barbarella to the works of Moebius, Don Lawrence's Storm, the works of Jack Vance including The Dying Earth and Planet of Adventure; Matthew Hughes' Henghis Hapthorn stories, and Rob Chilson's Prime Mondeign stories.