Athans, Sandra K. Secrets of the Sky Caves: Danger and Discovery on Nepal’s Mustang Cliff. 64p. bibliog. chron. further reading. glossary. index. maps. notes. photos. reprods. websites. Millbrook. Apr. 2014. RTE $33.27. ISBN 9781467700160; ebk. $24.95. ISBN 9781467725408. LC 2013017736. Gr 4-6–For thousands of years, secret caves have been tucked away in steep cliffs in Nepal, and mountain climbers and scientists have begun to explore them. Through their discoveries, they are able to learn about this remote area, its history, and the people who once lived in these caves. The author (a sister of one of the mountaineers) takes readers on a fascinating journey, blending adventure, science, and history. Sidebars of information add a depth of information from topics as varied as what gear a Mustang rope rigger needs to an explanation of a Bon manuscript dating back to the mid-1300s. The book design is attractive and accessible and includes quality photographs and clearly labeled maps. The book will enlighten young readers to one of the most fascinating explorations and discoveries happening today. Seven pages of back matter provide a plethora of additional information. This well-executed narrative envelopes readers in a captivating tale of true mystery and adventure.–Helen Foster James, University of California at San Diego