Sequence 10–3: The Observatory

Optional Missions:

- Incapacitate all guards while unarmed

- Incapacitate 5 guardians from stalking zones

Head to the marked location east of Charlotte. This is the last discoverable location which will contain more collectibles. Un-arm yourself and head inside the jungle. The guardians are natives hiding in the bushes who will ambush you when you're near. Use your eagle vision to find them in the bushes. The gauge in the upper left corner of the screen shows the number of guardians present in the area. Also, take note that you must knock them out using your bare hands for those to be counted towards the optional missions. It won't be counted if you use sleep darts to go around them. You can sneak behind them within the stalking area so do that to knock them them out.

Head to the first jungle area and move along the stalking areas to the right side since there are three guardians along the path. There's another guardian hiding in the bushes along the stream so don't miss him.

Head to the next area where there's guardian activity and stay on the right again. Tag the guardians using your Eagle Vision then move along the stalking areas. If ever you get detected, guardians will chase after you. Lose them and hide then attempt to subdue them. As long as you don't use your weapons against them and you knock them out from stalking zones, it will be counted towards the optional objectives. After knocking out five guardians from stalking zones, you can now climb the branches and wooden platforms to incapacitate them from the air. Find all the guardians in this area then clear them before moving to the next zone.

Head to the next part of the jungle where guardians are hiding. Climb up the wooden platform and take out the guardian patrolling there. Be careful of the swamp as well since there's a crocodile roaming the waters. There will be four guardians in this zone; one is on the wooden platform, two hiding in the bushes near the central tree platform and another one along the path to the cave.

Climb the viewpoint near the cave entrance to clear up the map. Enter the cave and knock out the guardians one by one. You're not required to take them out while hiding but you have to defeat them in battle without using weapons. There will be several chests and collectibles along the way too so don't forget to loot them.

Exit the cave and head to the last jungle area. Jump on the platforms then search the path along the waterfall to find two more guardians. Knock them out then follow the straightforward path leading to the out-of-this-world ruins. There are only three guardians left in the area so find them and incapacitate them all. Two should be patrolling the area and one is hiding in the bush near the Mayan Stelae. After clearing the area, climb the black monolith and synchronize with the waypoint.

Once done, Roberts will eliminate the witnesses and you'll have to follow him inside. Pick up the wooden tray containing some blood samples until you reach the altar. Place the blood samples there and watch the following scenes.

After getting trapped inside the area, climb the ledge to the north and you should be able to climb on the wall using the spaces. As you make your way around, you can also get an animus fragment along the way. Jump to the last ledge that will take you to a short tunnel leading outside. Slide down the slope only to get injured terribly. Approach Roberts and attempt to deflect any attacks from his men. You'll eventually succumb to your wounds and black out. Mission will be complete.