The Great Wall of China needs the Stone Bowl. It is in a tree at the camp of Lewis and Clark (8 o'clock 1805 AD). Climb up and grab the bowl from the animal's head. Return to the Wall, climb to the top left, and jump to reach the sentry on the left wall.
The Thor Amulet is at the upper right side, and the barrel of gunpowder at lower right. Both of these go to the Viking island (2 o'clock, 831 AD). The gunpowder will blast open the rocks when you click them, and you can enter the cave to get the golden vase.
The gunpowder is in China (1593 AD), by the wall to the right.
The Thor's Hammer amulet is at the great Wall of China (1593) - climb to the upper right and beat the old man in a memory game.
It is at 1593 AD on the time device (6 o'clock position).
Get the gunpowder from the Great Wall (1593 AD) and then click on the rocks.
To the far right in The Great Wall of China (1593 AD)
It is to the far upper right on the Great Wall of China (1593 AD, 6 o'clock on the time travel device). You will have to beat a memory game. While you are there, get the gunpowder at lower right, to open the cave on the Viking island.
The Great Wall of China is at 1593 AD, which is 6 o'clock on the time device. (see related question)
at 1593 ad to the right
Search up "How do you beat Time Tangled Island"
The cave rocks can be blasted away with the barrel of gunpowder from the Great Wall of China (1593 AD, 6 o'clock on the time device).
Time Tangled Island is on the site Poptropica. A link to the video walkthrough is provided below. For the written solution, see the related questions.
Be sure to leave any of the "challenges" on Time Tangled Island. If the time device still doesn't show up, reboot Poptropica to see if it will set you back to the start of 1593 AD.