The old parts of the city are smart buildings that produce solar power for lights and sanitation via solar cells built into the buildings' windows. A third of the structures currently in the city are of this age and design. Not bad for a city neglected for nearly 2000 years. The rest of the city is new constriction since the refounding in the 22nd century of Earth.
Ansisi and other friends were fleeing the dregs of the AI War via the The Express. Some place for the Outsiders was required, and raw living in the El Nanth system is not healthy. On Savanna Landing Town grew up around Jerry LaSaille's camp. The slowly decaying El-Aurian City on Glade was chosen for the Outsdiers because at least parts of it still worked. It was light and shelter where normally their would have been none. This fact alone kept the El-Aurian city from decaying to nothing, the fate of every other Outsdier structure built in the rosette without Ane permission.
The ministries of other Federation member worlds, or the embassies of non Federation member worlds are located here. Each is allotted an area to build its complex, or offered an empty, but suitable suite of rooms or structures. In extreme cases the Ane will have a site adapted to fit the special needs of the guests.
Crystal City holds the Memory One University campus. This university while dealing in all subjects specializes in history, considering the resource at hand. Enrollment is limited to 20,000. The Memory One public access facility is adjacent to the campus. This is open to any resident of Glade or visitor to the planet.
Crystal City is also the location for The main offices of Nanotech, producers of the Crystalmind computer systems. The headquarters of the Liggits Spacecraft Company, a producer of small craft (under 5000 tons). The offices of EverFresh Statis Systems, makers of the primary transport method for El Nanth produce. The offices of Waldo & Magic, the primary producers of the heavy Ane bios as well as medical and industrial remote handling systems. Stoner Medical Systems, the producers of the prosthesis style bios. As well as a major supplier of more modern medical marvels. And the main offices of Aurora Mines. Other Interstellar and local companies are also headquartered here, or have major offices.
High Crystal Station is considered part of the Crystal City Administration district. It has it's own constable force for practical reasons.