The two Jasper Islands, Big Jasper and Little Jasper, are home to both the Chromeria and the center of the Seven Satrapies' government. Little Jasper is entirely composed of the Chromeria itself, where the Spectrum, The White, The Black, and the Prism live and work, as well as the drafter academy. Big Jasper is home to merchants, artisans, ambassadors, shops, stalls, taverns, brothels, prisons, flophouses, tenements, warehouses, rope makers, sail makers, oar turners, fisherman, convict slaves, and "far more than its fair share of graspers, schemers, and dreamers."
The entirety of Big Jasper is enclosed with a tall and thick curtain wall, which was built in response to several invasions of the island, which never managed to touch Little Jasper, but purged Big Jasper in blood and fire.
In between the two islands stands Cannon Island, which, aside from protecting both of the islands from invasion, also houses an entrance to a secret tunnel that serves as an escape route from Little Jasper in emergencies, as well as a backdoor into the Chromeria. The Blackguards jealously protect the secret status of this tunnel. If anyone were to betray the secret of the tunnel, the Blackguards would hunt them down and kill them. Or, as Ironfist put it: "I'll tear your arms off and beat you with them."