The Glimmering Valley, a forthcoming hardcover for Numenera, gives you a fascinating and beautifully fleshed-out region from which to launch your Numenera campaign. It details an area of the Ninth World made specifically to be the origin point of a group of eager explorers. It brings Numenera back to its roots and gives players a place to call home. A place to defend if and when it becomes threatened—and a springboard into the many splendors and dimensions of the broader Ninth World setting.
The valley is filled with mysteries amid remnants of the prior worlds. The Glimmering Valley presents many opportunities to tie the player characters to the Ninth World’s weirdness as a part of their backstories, their families, their mentors, and particularly the origin of any weird abilities or technologies they wield. You can place the Glimmering Valley almost anywhere you like within the Ninth World, and let your campaign sprout from there.
PCs who make their way to the far end of the valley find a city where they can experience more adventures, or that they can use as a gateway to the larger Ninth World beyond the valley itself.