Chapterhouse
Chapterhouse is the Bene Gesserit name for whichever planet serves as the order's secret home base, held lightly enough to be abandoned without a trace.
Chapterhouse is not one planet. It is what the Bene Gesserit call whichever world is serving as their home base, and over the centuries of the order's existence the name has moved with them. A Chapterhouse is treated as temporary on principle: never fully settled, held so lightly that the Sisterhood could leave at short notice and leave almost no trace of having been there, which is a loose use of the word, given that one of them served for more than fifteen hundred years. The Sisterhood's main library is kept there. Its settlements include Central, where the Chapterhouse Keep stands, along with Pondrille and Eldio.
How far into Dune have you read?
Set your place and this page rewrites itself to exactly that point. Nothing ahead of you will show.