This hideout is mostly underground, inside the mountain with several entrances into the hideout. Two entrances are located on the east side, just off the main road. Big holes provide access into the middle of the base. Duck into a small opening just below the ruins on the southwest side to reach the start of Side Quest: Taking Liberty (if available). The commander splits his time between this cavern and outside around the ruins.
At the aqueduct’s west end, follow the water into a cavern. Climb the waterfalls on the right, and scale the tall cavern until you reach enemies above. Keep an eye out for the captain along the way. If he isn’t near the water below, he may be training at the top of your climb or guarding the east entrance to the right.
One treasure is shown on the map, next to a pillar in the ruins. The other is inside the mountain, near the eastern entrance. From the cavern, just inside the eastern entrance, move into the south corridor. Destroy the clay pot that sits next to the table. Slide into the hidden room to find the second treasure.