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Ancient Archives is a point of interest within Melandru's Hope in The Echovald Wilds. It's a cathedral like building with a Jade Teleporter entrance, guarded by an Elite Canthan Spirit Tahkayun. On the outside, a Jade Battery can be found next to the broken down Teleporter. Inside the building is a Mastery Point.
On the western side of Teleri Village, you'll see a building with a Jade Battery on its southern side. Use the Jade Battery and use a Zip Line from behind the building surrounded by trees. Once you reach the other side, you'll be able to see the next zip line. Keep using the nearest zip lines until you get to the bridge. Cross the bridge and at the end there will be a broken Jade Teleporter guarded by an Elite Canthan Spirit Tahkayun. You need to use one Jade Power Charge to fix the teleporter and one more to use the teleporter to get inside the Ancient Archives.