When I was a kid, I loved stories with hidden treasures and secret tunnels. They often appeared in the stories I read in the Hardy Boys and Three Investigators series, as well as the Trixie Belden and Nancy Drew books that a spinster aunt allowed me to borrow. This week we’ll look for hidden treasures, and next week we’ll go tunneling.

Stories

The Stratemeyer Syndicate produced the Hardy Boys, Nancy Drew, Dana Girls, and other children’s series. If you are ever curious about them, many of their titles can be checked out and read online for free at archive.org.

The first three Hardy Boys books entered the public domain in 2023. So we can copy, distribute, recast, and remix them at will, as no one can own them anymore. And over the next 50 years, the additional original 58 books will steadily lose their copyrights. However, Harriet Stratemeyer Adams published revised versions of the Hardy Boys books from 1959 through 1973, and those revised works will remain under copyright for 95 years after their first publication.

The Hardy Boys series included dead-on titles like #1: The Tower Treasure and #5: Hunting for Hidden Gold. The original versions of the early books by ghostwriter Leslie McFarlane are far better than the revisions, anyway. The originals are products of their time and do suffer from some racial stereotypes, but they are rollicking adventures that I read and re-read in elementary school. I know that some of my self-confidence and self-reliance was sparked by his formative tales, even if I had to ask my folks what a jalopy was or where on a car you could find a rumble seat.

McFarlane wrote 19 of the first 25 Hardy Boys books between 1927 and 1946, plus two more later. He could write one in about three weeks, earning maybe $100 to buy coal to keep his Canadian family warm. Funly enough, he also wrote the first four of the Dana Girls books that my aunt loaned me. And despite rushing to write them and never revisiting them later, McFarlane didn’t write trash. Here is how he stoked my imagination when writing about a storm in Hunting for Hidden Gold:

The snow flung itself upon them and the wind shrieked with renewed fury as they left the unsheltered pit and entered the half-darkness of the cave mouth. It was as though they were entering a new world. They had become so accustomed to the roaring of the gale and the sweep of the storm that the interior of the passage seemed strangely peaceful and still.

from Hunting for Hidden Gold, in 1928 by Leslie McFarlane, as Franklin W. Dixon

Nancy Drew had some spot-on titles as well. The first 34 volumes were also revised from 1959 to 1975. One of my favorites was the original 1945 version of #22: The Clue in the Crumbling Wall which my spinster aunts had tucked away high up in a closet. In that adventure, the hidden treasure was, surprisingly enough, bottles of magenta dye made from whelks and notes allowing a chemist to create color-fast versions of it. That intrigued me, and I would read again of valuable dye from sea snails when I took Latin in high school and college and studied Roman history. I learned that treasures come in many forms, not just precious metals, money, bonds, or jewels.

Although the Nancy Drew series is credited, like the Dana Girls, to the pseudonym Carolyn Keene, Nancy was born from the typewriter of Mildred Wirt Benson. She ghost-wrote 23 of the first 30 Nancy Drew books for a flat fee of $85-$250 from 1927 to 1953, with the first book published in 1930. Her first three books will enter the public domain in 2026.

Buried Treasure

Perhaps the most famous buried treasure comes from Treasure Island by Robert Louis Stevenson. At the conclusion, the protagonist Jim Hawkins described it thusly:

It was a strange collection, like Billy Bones’s hoard for the diversity of coinage, but so much larger and so much more varied that I think I never had more pleasure than in sorting them. English, French, Spanish, Portuguese, Georges, and Louises, doubloons and double guineas and moidores and sequins, the pictures of all the kings of Europe for the last hundred years, strange Oriental pieces stamped with what looked like wisps of string or bits of spider’s web, round pieces and square pieces, and pieces bored through the middle, as if to wear them round your neck—nearly every variety of money in the world must, I think, have found a place in that collection; and for number, I am sure they were like autumn leaves, so that my back ached with stooping and my fingers with sorting them out.

from Treasure Island, Chapter XXXIV: And Last, in 1883 by Robert Louis Stevenson

The book famously opens with a map to buried treasure on Skeleton Island which propels the plot. Three crosses of red ink on it evolved into the famous “X marks the spot” in popular culture.

In 1894, Stevenson told the story of how he came to write the book. He conceived the idea for the novel based on a map of an imaginary, romantic island which he drew with his stepson Lloyd Osbourne during a holiday in Braemar, Scotland in the summer of 1881. Sadly, when he submitted that map with the manuscript of the novel to the publisher, the map was lost. Stevenson had to recreate the map from memory, combing through his own text to ensure everything matched up.

Hidden Safes

A hidden treasure trope of television and movies is a wall safe hidden behind a picture. Adam West’s Batman spoofed that in 1967 by showing that the Wayne Foundation’s safe was hidden behind a painting…of that safe.

In the real world, the fabulous Marland Mansion in Ponca City has one wall safe intended to hide liquor during prohibition and another in a cedar closet which I presume was for jewelry. I guess it was meant to be hidden behind mink coats?

An old house I lived in during elementary school had a safe, but it was better hidden. The original part of the home had two bedrooms, with a smaller one designed for kids, complete with windows strategically positioned for bunk beds. That room featured a built in counter with a desk and cabinet, and there was a square panel in the bottom of it that you could pry up to reveal a small safe embedded in the slab. It opened with a key, and one was snapped off in the lock when my parents bought the house. A locksmith got it working again, which reminds me of what Harriet Stratemeyer wrote about Frank in the original 1946 edition of #25: The Secret Panel:

The Hardy boy found another book on the history of locks and keys, which looked so fascinating that he turned on a reading lamp and sat down in an arm-chair to glance through the volume. He became completely absorbed in the subject, learning first that in Biblical times keys were made of wood and were so heavy they had to be carried over one’s shoulder; that later the makers of metal keys received the name of locksmith because actually they were blacksmiths who forged keys; and that the invention of truly burglarproof locks is barely a hundred years old.

A secret panel with a hidden safe was a dream come true, but of course my parents knew all about it. So I remember searching my own adjoining room for secret hiding places. That had been the parents’ bedroom in the original two-bedroom house, and it had two closets on one end with a make-up counter between them. A large tilted mirror was mounted above it, and I found I could remove the decorative screws at its top and tilt it down. That revealed a wooden panel with a square hole in the middle. Imagine my disappointment when I found nothing in the dead space behind there.

It was simply too difficult to use that hiding place, as I knew I’d be in big trouble if my parents caught me mucking about with the big mirror. So I remember choosing not to use it, instead stuffing notes into a gap behind some molding. I recall that one was something about my fear of death, which was a brief obsession when I realized that everyone dies. That reminds me of the secret tree/temple in Wong Kar-Wai’s marvelous In the Mood for Love.

Finding Hidden “Treasures”

Few of us will ever encounter an actual treasure map, although your smartphone can become a type of treasure map if you enjoy geocaching. My first experience was with my friends the Falkners at Red Rocks Park in Colorado in 2001.

I didn’t take up the hobby, but in 2012 I accidentally discovered a geocache in a dead tree at Hartman Rocks at Gunnison, Colorado while recovering from altitude sickness.

Wendy spotted another geocache in 2015 when we were hiking on the remnant of the Standing Rock Nature Trail at Lake Tenkiller in Oklahoma.

But what about buried treasures? If you don’t have a map and the treasure is conductive metal, then you’ll need a metal detector.

There was a metal-detecting craze in the late 1970s and 1980s. My father had a Garrett model that found many an aluminum pulltab despite his attempts to set its discriminator circuit to ignore them. Ernie Fraze invented pulltabs in 1959 and they quickly littered the earth. Things improved in the late 1970s when Daniel F. Cudzik invented the stay-on pop-top.

So how do the detectors work? They have a coil of wire that transmits an electromagnetic field into the ground. Alternating current makes the field pulse up and down. That induces electrical current in conductive metals in the ground, generating a field of the opposite polarity (Lenz’s Law). So when the transmitted field pulses downward, the object’s induced field pulses upward, and vice versa.

The most common type of detectors have a second receiver coil. The induced field pulsing from the buried objects induces a current in the receiver, which is amplified and can be used to make a meter respond and to produce sound from a speaker.

Metal detectors go way back. Five years after receiving his telephone patent, Alexander Graham Bell invented the metal detector in 1881, in an attempt to locate the assassin’s bullet inside President James Garfield. Metal detectors took off as hobby devices in the 1970s due to technological improvements and surging gold prices.

In 1968, Charles Garrett began manufacturing detectors that eliminated oscillator drift, improving their power and accuracy. Then very low frequency detectors were introduced, which could detect small objects like gold nuggets and detect coins buried as deep as 10 inches. The addition of discrimination circuits to eliminate signals from iron and foil reduced frustrations. But what really drove the fad in popular culture was that in the 1970s the price of gold trevigintupled. Trevigintupled? Okay, that’s a truly obscure way to say it went up by a factor of 23.

My dad bought a Garrett detector, and he had great fun searching for treasures on vacations, at parks, etc. His interest was more resilient than my own. There were too many pulltabs and junk with too few coins to hold my interest.

Our last shared metal detecting outing was in 1994 when we dug at an old homestead in the Missouri Ozarks. By then he had a simpler Bounty Hunter detector along with his original Garrett. We found a few items, and he later returned on his own to thoroughly explore the site, finding quite a collection of junk. Dad truly delighted in his finds, even though they were hardly treasures to anyone else.

I realize that I am more interested in reading about treasure hunting than actually joining the search. Real-life hunts that come to mind include:

• The old mystery of Oak Island, which has come to be associated with the term “money pit” in popular culture.
• The Fenn treasure, which took a decade for someone to find.
• Mel Fisher’s recovery of the treasure from the wreck of the Nuestra Señora de Atocha galleon.

Well, that’s enough rambling for this week. Next week, we’ll explore secret tunnels.