The Lost City - Freeing the Third Trebuchet from the Ice (Part 1)

This sequence is also shown in a short video walkthrough.

Stand on the red painted ledge in front of the trebuchet facing the wooden armature.

Shoot the right end of the beam (i.e., the lower end with the golden bucket) with a rope arrow to pull the beam around toward you.

Jump onto the beam.

Walk to the upper end and then jump onto the tower to the left of the falling water.

Go around to the right to find an Explorer Satchel (2/2), which reveals the locations of the 3 survival caches in the southern part of the city, assuming you haven't already found them.

Stand next to the wooden bucket and shoot a rope arrow into the upper end of the balance beam. This attaches the bucket to the beam.

Slide down the zip line on the right. Search the container for herbs or cloth and possibly a few gold coins.

Then hop down onto the ledge below, which is level with the base of the balance beam