Award-winning author: 2020 Readers' Favorite Silver Medal *** Which was the first country to give the citizenship to a robot? Is the dark side of the Moon always dark? What is the Sismo Detector? Discover the answers to these seemingly random facts and more! The interesting trivia in this page-turning fact book were collected by Nayden Kostov, founder of the RaiseYourBrain website and author of popular fact books such as: "1123 Hard to Believe Facts" and "853 Hard to Believe Facts." As the third installment of this series, 523 Hard to Believe Facts has more detail for each fact, as requested by previous readers. And what's more, it is also available as an audiobook!These facts are a result of years of sifting through history and reference books, as well as searching the Internet and researching the news. Each fact is suitable for nearly any age - the "spiciest" entries are separated by their own chapter but still use clean language! Become a trivia whiz with even more facts in the Hard to Believe Facts series!