For people who have a hobby of reading and solving puzzles, here is a boon for you. How about both of them together? Codex Silenda is a book that needs to be solved physically if you wish to read it ahead. It comprises of math and mechanical problems that are cut in wood using lazer and only when you solve the mechanical puzzle, you can navigate to the next page.
As of now, it is funded by Kickstarter and created by Brady Whitney. This series of books is bound to keep you engrossed in it and it will definitely be a one of a kind experience when you read and solve this book.
