PERN, 13th Pass
Pern 13th Pass
* Of the original weyrs, only three remain - Igen, Telgar and Fort. Ista and Southern Weyrs, as well as Southern Hold, fell into the sea in the 10th Pass as the seas rose. Benden, which was acting as a secure place for important documents at the time, was overthrown and burnt by Holder-folk in the 10th Pass, when the new Weyrleader and Weyrwoman refused to fight deadly Thread out of denial of its continued existance. High Reaches was flooded when the glaciers of the snowy wastes receded and the mountains once again reclamed their territory and hallowed lakes. Any of the four destroyed Weyrs' Holds were renamed.

Pern's Map is shown above with all current Weyrs labeled.
FYI: Moon Lake's third Daughter Weyr, DarkMoon Weyr of Weyrwoman Inala (Srinia's daughter) is located on the Western Isles. Galen, Moon Lake's second daughter Weyr is located on the Southern Continent. Baindol, Moon Lake's first daughter Weyr is not shown due to inactivity.
* On the Southern Continent, there are four Weyrs: Eastern (far west), Moon Lake (central and former southern territory), and Moon Lake's Daughter Weyr, Galen (secluded, mountain region) and Alliance member Black Sands (east Sea of Azov).
* The Northern continent has several new Weyrs, includeing Tiazora, one of the allied Weyrs.
* the Western and Eastern Island chains have several Weyrs.
* Mutations are common, localized and vary from Weyr to Weyr.
About Thread
* In most areas the grubs that destroy burrowing Thread have been destroyed. These areas, called weakspots, are unknown, so dragons must get as much Thread as possible and be very meticulous.
* The Red Star was not desroyed by AIVAS, it was simply twisted in its orbit closer to Pern. Threadfall is now heavier, but passes have become less frequent, however, unpredictable. All info on AIVAS was destroyed when Benden was destroyed.
* And yet, the Harper Hall and its Records endure.