Before these "Where Is" books came out, this series began with Who Is/Was. I used these in my 4th grade classroom for a biography study, finding them to be much more interesting and readable than most other available biographies for middle schoolers. I no longer teach 4th graders, but was completely caught up in Where Is Area 51? It seems really well researched, and eye-opening ... I learned a lot! I read this as an adult for enjoyment because I do NOT LIKE nonfiction, can't get through it, and this fascinating book kept my attention for all 108 pages! Can't wait to read the next one.