First of all, COORDINATES and ACCESS:
Antar VI, -634 N, 200 E, Alt 98
From Trung’s Nova Golda Market (there are many ways to reach Nova Golda, but I know best TNT’s Trung portal and Ultima as access points) :
Screenshots for Nova Golda Directions
Go to Nova Golda, go downstairs in the portal area and find the 2x1 portal with a sign with my name on it; you’ll be at the place then.
NG Ultima Access
NG TNT Access
Alternatively, from Ultima’s main Hub:
Screenshots for Ultima Directions
Find the Antar VI portal at Ultima, go through, find Portal 5 then and you’ll be there.
The Fortress can now also be reached via Anterra Central on Antar VI
Also available on the outskirts of the fortress is a good Antar VI gleam [Weary Violet] farm spot. Simply go down the ramp from the shopping area, across the bridge and find the rock “clam”.