The second document was a record of the pyramids.
The mere existence of pyramids defied common sense because it was impossible to build such structures using the technology present at the time. Later research by people studying the pyramid revealed a plethora of many unimaginable things, forming the source of many legends.
Ye Lingchen took his time to read it. Based on the rumors, many people who entered the pyramids died bizarrely. In fact, they did not enter the pyramids for the sake of fame, but were elites chosen jointly for an expedition by various countries. In the end however, every single one of them did not come out alive!
Elites chosen jointly by different nations?
Ye Lingchen was keen enough to take note of that information. Elites were mentioned in both documents, and his guess was that they resembled warriors!
Those individuals surely had ample strength!
In that case, the pyramid was probably the second Hell's Gate.