The Secret - A treasure hunt - San Francisco

This is my theory to find the secret location for the San Francisco casque from the book The Secret a treasure hunt by Byron Preiss. My first language is french from Canada so this explains my accent. Feel free to share other ideas in the comments. If you do find the treasure with this theory I am not asking for much, you can build a shrine or a monument in my honour, something simple. You can use the Taj Mahal as a template, thank you.