This book introduces the reader to the fast-growing outdoor sport of geocaching, which combines aspects of treasure hunting, high-tech navigation, and exploration. New to this book: --Updates to technology and use of social media. --Full chapter on smartphone apps. --Updates to photography-showing more technology and diversity of participants. --Mention of National and State Parks, which are now promoting geocaching. --Updates to swag, with official geocaching containers, special edition coins, and micro containers, etc.