Shadow Weyr is situated on the mountain of a lush island just off the West coast of Southern Pern, the half-circle shape of the top of the mountain making it an ideal place for a Weyr to be. So thought Moreatha of Gold Arionoth and her rider-helpers when they first explored here, searching for a place for the ever-populating Fort Weyr to expand to.

At present Shadow Weyr, as this mountain and its cavern system was dubbed, is a slowly growing center for the Dragons of Pern. Named for the strange things glows do here - something makes them less bright, sometimes simply making them flicker - the Holds that tithe to Shadow are Dragon Wing Hold, Fire Beach Hold, and Dark Waters Hold. Dragon Wing Hold is located on the northern side of the enormous Shadow Island, Fire Beach and Dark Waters more to the east. The Weyr itself is on the island's largest, rounded mountain, near the sea to the east and south of Shadow Island. A small lake is located in the Weyr Bowl, which opens out to the warm sea and grassy plains.