Hotep Cavern (Location)
An out of the way cave in the Qattara Depression, east of Siwa.
Scans show the two treasure close together, deep in the cave.
Clear the local hyenas, then venture inside to find the treasures in a half-buried chest, and the loot pouch of a corpse.
Looting both completes the mission.
Which is a little disappointing, as this is clearly the cave where Layla is using the Animus in the present day. Still, there's nothing more to do here… yet.