"Only the most magnificent royal tombs would have side doors or alternative entrances built into them," Andrew said.

Kevin nodded. "That's exactly right. Royal burial grounds often took decades to complete. Emperor's tombs especially, would begin construction the day they took the throne. Some took up to 50 years to finish.

"Because of this, they inevitably had to create multiple side doors and alternative entrances. This made it convenient for craftsmen to come and go and allowed the emperor or high-ranking officials to come down and inspect the progress themselves!"

Chantelle asked curiously, "Wouldn't the emperor use the main entrance when visiting his own tomb?"

Andrew shook his head. "The emperor would only go through the main entrance once—on the day he was buried. Every other time, he couldn't use the main door and had to use the side entrances instead."

Kevin was getting impatient. "Come on, let's hurry up and climb to take a look."

The nearly vertical cliff face co