Hardcover book, 1st edition, copyright 1911: "Mammoth Cave Romance" by William Lee Popham. 111 pages of text. Unillustrated except for two photographic plates in the middle of the book, depicting Mammoth Cave. Book does not have dust jacket; boards are navy blue fabric with cover having embossed gold lettering; there is no text on the spine.
Book is significant for being one of the "Seven Wonders of the World Series" by this author; all are set in parks or significant American locales, i.e. "Mammoth Cave Romance," "Niagara Falls Romance," "Garden of the Gods Romance," "Natural Bridge Romance," "Yosemite Valley Romance," "Yellowstone Park Romance," "Washington Monument Romance."