I think Sinny is correct:-
Opening Quest Line to Activate Fae Circles
Once you have unlocked the first tier,
Nurtured Roots, you will need to activate your mushroom network by assisting the Chief Mushroomancer, Cortinarius, located outside The Stalks. You will need to complete this quest line to open the network. You receive this quest from Aithlyn in the Heart of the Forest. (Quests marked as faction specific are available to both sides).
Silence in the Stalks - Speak to Cortinarius in the Stalks.
Mushroom For Improvement - Plant mushrooms on 15 Masked Fae in the Stalks.
Ring Repairs - Repair 6 Damaged Mushrooms.
Fighting For Fungus - Help Cortinarius defend Marasmius
My Way or the Hyphae - Ride the fae rings with Marasmius and defeat 30 invaders.
Through the Veil - Find somewhere to plant Marasmius in the Heart of the Forest.
Once you have completed this quest line, you can now access the main hub of your portal network, The Ring, through the spell
Fae Rings. Inside your Sanctum, this is located in the northern part of your Sanctum, in a room below the ramps leading to the Flight Master.