The Great Northern Library is in the southern region of The North in the hills near a large lake. The route to the library is a protected by two great standing stones, written with the word of Juvens, so that no man with violence in mind can find the path to the library. The library complex is surrounded by a weathered and mossy wall built into the cliff, and can be entered by a single gate across a bridge over a deep gorge. Within the walls is a small village of people and the library itself; three great, tapering towers built into the mountainside ahead, joined at their bases but separating higher up. It is now the home of the Magus Bayaz, the first apprentice of Juvens.
The Great Western Library is in a region with no name to the west of the Old Empire over the Broken Mountains. It is located in a dilapidated and slowly decaying village. The library is a huge and jumble of buildings of various confused shapes and styles. Three tall, round, tapering towers sprouted from their midst, joined at their bases but separating higher up; one tower is broken off before the summit, its roof long fallen in. It is now the home of the Magus Cawneil, the third apprentice of Juvens.
These are the only confirmed libraries, but it’s hard not to speculate that Sarkant the fortress-temple of the Magus Khalul is the Great Southern Library. There's no evidence at all of the Great Eastern Library if it even exists, and it remains an Unanswered Question.