It was a normal day when John got the box came in the post. He opened it and found a handful of objects inside. He picked out a piece of paper and on it was a riddle:

The next clue lies within the top rung of me
I am controlled by the 6 The key to me is found within this box
I will lead to the richest treasure you will ever know
Use the key, and you will gain the knowledge to solve this

Fishing through the box, John also found a pendant:

He also found a small object. It was a transparent hollow tube with a piece of paper inside. The paper had written on it you. John turned over the tube and found in small bumps the letters 7nAZqPqlz1M

Where is the next clue, and in which country can it be found?