As I wander through the Streets of Yesterday, peeking into replicated 19th-century storefronts, a circus-like cacophony begins reverberating through the air. Curious, I stride toward the music, glancing at a group of people surrounding a fortunetelling machine, where a mechanized Esmeralda is dispensing prophecies printed on tiny cards.

At the end of the street, an immense music machine called the Gladiator Calliope has sprung to life. As high-pitched toots, trills and whistles erupt from the steam-whistle organ, a line of mechanized gladiators clutching sticks and mallets strike a drum, cymbal and bell. At their feet, invisible breaths blow across ceramic jugs.

"Oh, my gosh, this is insane," someone in the crowd whispers.

Rounding the next corner, a snarling, 200-foot-tall fiberglass sea creature improbably rises from the floor, as the Beatles' "Octopus's Garden" gaily plays.

Welcome to the House on the Rock, one of the nation's more notable roadside attractions. It's a hard-to-describe mélange of art, history, music and fantasy that excites and amazes you one minute, then leaves you bewildered and unnerved the next.

The destination outside Spring Green, Wis., has also gained notoriety for its physical and mental challenges: Visitors once had to walk through the entire three-plus-hour experience, squeezing through some narrow passages and climbing to heights that some found unnerving, before they could exit.

Today, you have the option of touring one, two or all three sections of the House on the Rock. And for guests with claustrophobia or acrophobia, brochures note that they can tap employees for help in finding alternate routes.

How it all began

The House on the Rock was never intended to be a public attraction, much less one so immense and unusual. It began innocently in 1945, when a young Alex Jordan Jr. wanted to build a hideaway at Deer Shelter Rock, a 60-foot stone tower in southwestern Wisconsin. Jordan's family helped him purchase 240 acres, and he spent the next decade-plus tirelessly working to construct a home on and around the rock. Locals called him "the mountain goat," as they witnessed him repeatedly place stones and mortar into a basket, strap it to his back and haul it up the rock via ladder.

Fast-forward to 1960. Jordan's fantastical home was largely finished, although it wasn't so much a house as a collection of cozy nooks and fireplaces with massive hearths. Unfortunately for the private Jordan, the number of people who regularly begged for a peek inside grew uncomfortably high. To drive them away, he said tours cost 50 cents. To his dismay, they gladly ponied up.

At the end of the year, Jordan had raked in a surprising $5,000 from his tours. The following year, he bagged $34,000 — or $340,000 today, when adjusted for inflation. He never looked back.

Now officially operating a tourist attraction, Jordan began amassing random collections for additional displays: bisque dolls, swords, scrimshaw artwork, Burma-Shave advertising signs. Then he built a network of sprawling buildings to house them all. These structures also contained his various creations, such as the Streets of Yesterday, that enormous sea creature and a variety of music machines that eerily spring to life when fed a token.

"Alex loved musical machines and made sure he always had skilled workers that could create the machines he envisioned," says Jennifer Greene, the House on the Rock's director of operations. "Alex was in complete control of the process and had the perseverance to make his dreams come true."

Two of those dreams were to create an Infinity Room and the world's largest indoor carousel, which today are guest favorites. His Infinity Room is a 218-foot glass-walled, cantilevered platform that juts out over the Wyoming Valley 15 stories below. His massive carousel, set aglow by 20,000 lights, holds 269 centaurs, dragons and other fantastical creatures — but no horses.

Mystery is the point

As my group wanders through the attraction, which today also features a welcome center, interpretive center, two Asian gardens and an extensive system of exterior walkways, we continue to be shocked, amazed and baffled by what we see. A 1963 Lincoln Continental with suicide doors that's completely covered in blue patterned tiles. An antique, multi-barreled pistol akin to a mini-machine gun. A bright red "humor tester" chair which, after a token is deposited, reveals whether your temperament is that of a sourpuss or a clown.

"It's so improbable that something like this exists," says John Junghans, a member of my party visiting from San Antonio.

Soon questions begin bubbling out of us. Why is there such little signage to explain what we're seeing? How did Jordan pay for everything? Are the mechanical instruments really playing, or are we hearing recorded music?

"I want to know all of this," says my daughter Maura, "but I'm actually glad they don't tell us. It adds to the mystique."

Exactly, says Greene. "Alex Jordan was very committed to not supplying a lot of information," she says. "He wanted the House on the Rock to be a mystery, and one that would amaze and captivate guests. He was not looking to create a museum."

To keep visitors engaged, Jordan carefully sited his collections and creations so that every room contained items appealing to a variety of tastes. He also took delight in placing pieces in a contrary and even shocking manner, perhaps to keep visitors unbalanced. To wit: In section three, dainty bisque dolls slowly spin around on carousels, while a creepy, skeletal rendition of the Four Horsemen of the Apocalypse hangs overhead.

After departing the House on the Rock, we immediately pass Taliesin, the home and studio of renowned architect Frank Lloyd Wright. Wright would have been putting the finishing touches on his lifelong masterpiece just as Jordan was working on a masterpiece of his own, a few miles away.

Surely, both men appreciated the irony.

Melanie Radzicki McManus is a travel and adventure writer. She lives near Madison, Wis.

The House on the Rock

Where: 8 miles south of Spring Green, Wis.

Hours: 9 a.m.-5 p.m. Thu.-Mon. through May 14 and from Sept. 25-Nov. 12. Daily May 15-Sept. 24 and Nov. 16-Dec. 31. Arrival before 3 p.m. is recommended.

Admission: $20-$36 adults.