The gunpowder is in China (1593 AD), by the wall to the right.
To open the cave at 831 AD, get the gunpowder from the Great Wall of China.
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).
The gunpowder is to blast the rocks blocking the cave entrance at the Vikings time (831 AD). The gunpowder is at the Great Wall of China (1593 AD).
The cave is at the Viking time, 831 AD (2 o'clock on the time device). To open it, you need the gunpowder from the Great Wall of China, 1593 AD (6 o'clock on the time device). When you have the gunpowder, click on the cave to blast the rocks.
In the land of the Vikings, go right and up the hill, that's where the cave is. You need the Gunpowder to explode the rocks so you can enter the cave.
When you have the barrel of gunpowder from the Great Wall of China (1593 AD), you can just click on the rocks at the cave (831 AD) and they will be blasted away.(There is no USE on the gunpowder.)
The barrel of gunpowder (lower right at the Great Wall of China, 1593 AD) is used to blast open the cave at the Viking island at 831 AD (2 o'clock on the time device).
The gunpowder from the Great Wall of China (1593 AD) is used to blast open the cave at 831 AD, which is blocked by rocks. (see related question)
The cave at 831 AD is covered by rocks. Get the barrel of gunpowder from the right side of the Great Wall of China in 1593 AD. Clicking on the rocks will automatically set off the gunpowder and open the cave. (see related question)
The gunpowder from the Great Wall of China (1593 AD) is used to blast open the cave at 831 AD, which is blocked by rocks. (see related question)
The gunpowder at the Great Wall of China (1593 AD) is used to blast open the cave at 831 AD. (see related question)
There is a barrel of gunpowder at the Great Wall of China (1593 AD). You can use it to blast open the rock cave at the Vikings island in 831 AD. One you have the gunpowder, click the rocks to blast them open.