Climb around the corner to your right and make your way to the top of the platform. Take a left past the second sandbar and continue straight until you pass the arch on the back of the larger island. Once everything falls into place, walk to the switch that appears and interact with it to trigger a cutscene. In the base of the tower on the big island. There's a stone staircase at the top of the beach - climb it then cross the small rope bridge to the left.
Climb around the corner and drop down to the grassy shelf, then continue inland. Interact with the large wheel in the center of the room after passing through the door. Vault out the window and continue up the side, climbing around to the right. The next arrows will lead you out beyond the channel to two sandbars.
On the back side of the smaller island is a very little beach with a few palm tress.
This wheel controls large stone spheres mounted on the wall which must be aligned in accordance to the various light patterns on each ring of wall. Monkey-bar across the wooden boards and leap to the long beam across from them.
In the cistern planning room, Nathan will draw the miniature neighborhood.
Instead of climbing up the wall to get to the building Sam is in, go right around the wall to find a little cave.
Hook your rope to the anchor on the cliffside, then swing to the ledges across from you on the right. Return to the boat and follow the arrow across the water to the beach on the opposite side. This page contains the walkthrough for Chapter 12: At Sea in Uncharted 4: A Thief's End. Then you can throw the hook in mid-air, but you've gotta be quick. Boost Sam up to the rope ladder and wait for him to cross the bridge. In the provisions room of the cistern.
The treasure is hanging out in an open crate.
Shimmy to your left, drop down and jump the gap to rejoin Sam. When it falls, use the slats as a ladder to reach the top of the rock wall above you. Instead of dropping down, climb up the rope and swing over to the statue's base. Finding the main doorway blocked, climb up the rock wall into the cave to the left of the collapsed entrance. Look at the statues and Nathan will be able to take a note. After the cutscene ends, weave through the rocks and sandbars until you find yourself between the two larges islands.
Walk behind the rocks on the beach and you'll see the treasure.
There is a tresure near the barrels at the back of the beach. Interact with the large door and complete the QTE to get through it and reach the wheel chamber. Returning towards the cave entrance from the sunken ship, there is an overgrown beach on the large island to your right. Interact with the marking on the wall to trigger a cutscene. Once at the top, turn left and walk across the top of the archway, then cross under the rope bridge.
After Sam briefly goes missing and him and Nathan reunite, Sam will walk over to a cliff and comment on the view. Climb up the left side of the column (the side facing the entrance you drove the boat through), then use your rope to swing across to the far wall. The latest title in the Uncharted series is the first in this third-person adventure series on the Playstation 4 game system. Return to the base of the Avery statue (where you first docked at the beginning of the chapter) and climb the stairs. Swing to the ledges on the underside of the peak, then re-anchor your rope to swing across to the next rock formation. At the base of the second statue with the spear on the way down the Cistern.