National Geographic Society's coffee-table book entitled Caves: Exploring Hidden Realms, authored by Michael Ray Taylor, would certainly meet the criteria as being one of the most outstanding introductions to the mysteries of the underground. The tome is the companion text to the McGillivray Freeman Imax film by the same title.

Taylor separates the book into three distinct sections - ice, water and earth - in order that we have a general understanding as to where caves are to be located as well as their respective formations. As the author states: "the skin of the world hides many caves. All are profoundly shaped by, and profoundly affect, the nature of the land overhead. Caves are to a surface landscape as veins and capillaries are to a human face - the hidden structure of an inseparable whole."

The ice section introduces us to the caves of the heartland of Greenland where glossy photos provide us with fantastic visual entertainment that convey to us the beauty of these caves as well as the danger constantly prevalent within. Moreover, we are also clued in to the many animal creatures found within these subterranean enclaves such as the tardigrade. It is to be noted that the study of life in caves is known as biospeleology.

Our adventure moves onto to some of the caves discovered beneath the Yucatan or the section dealing with water. One only has to stare at the introductory photos to this chapter and we can appreciate the utterances of the cavers when they assert: "we are amid the wildest scenery we had yet found in Yucatan; and, besides the deep and exciting interest of the ruins themselves, we had around us what we wanted at all other places, the magnificence of nature."

The final stop on our journey delivers us to the caves of the earth where we explore the deepest one in the United States, Lechuguilla located in New Mexico. We also venture into the caves of Tennessee, Alabama and Georgia or as they are termed the TAG region. The spectacular photo of the Lechuguilla certainly reaffirms the statement that "a picture is worth a thousand words."

Enhancing the usefulness of the book are the many articles pertaining to the study of caves that have been contributed by several well-known experts. These short essays also include those of the author, Michael Ray Taylor, who has explored more than 600 caves in expeditions that have taken him around the world.

Bon voyage on your next expedition into the world of caves where all you will need is a good chair and Michael Ray Taylor's brilliant book.