There has never been a more excited librarian than the one called Ernesto who's in your Amazonia city right now! He keeps shouting "it must be real!" and "I have to find it!". What can he possibly be talking about?

Well, he thinks the mythical city of El Dorado really exists! Why is that great? It's made entirely of gold and hides the biggest treasure you've ever seen. Let's collect all the clues we can about it in the library.

Diggy needs to find 5 books 📚️ and put them on the table. We are looking for ones with a brown cover. They contain clues about how to get to El Dorado.
In order to get one of the memoirs of El Dorado, Diggy needs to solve the pit puzzle (in case you do not know how to pass it HERE is a walkthrough video):

To find one of the secret rooms with the memoirs of El Dorado, please pull the following lever ...

... enter the following entrance ...

... and solve the pit puzzle (in case you do not know how to pass it HERE is a walkthrough video):
Another one memoirs of El Dorado will require to solve the pit puzzle (in case you do not know how to pass it HERE is a walkthrough video):

Once you get all 5 memoirs of El Dorado, return to Ernesto and place them on the table:

All those clues will help us find the golden city of El Dorado.

In case you are curious about what all the symbols on the ground do mean, please place two golden lions on the following spots ...

... and then push the buttons in the following order:
