This book very much reminded me of the show Lost. A mysterious land with hidden borders, hallucinations and at its core, a tunnel (tower?) with a possible omniscient being running things. Even the people taking part in expeditions to discover what lies in Area X are possibly being manipulated by some government or organization. The narrator, along with the other characters are not given names, rather they are called by their fields of study. The bare bones character development created an even more haunting atmosphere, allowing Area X be the main focus. 
 The book will leave you with no answers, only suggestions, which will leave you with hours of conspiracy theories to ponder. But don't worry! The other two books in the trilogy will be released this year as well.