Unearthing a time capsule should be an exciting affair, a chance to see mysterious items hand-picked long ago as apposite examples of a bygone era. Unfortunately, these buried tubes of old garbage rarely live up to the hype.

"Ninety-nine percent of time capsules will remain boring as hell to the people that open them," says Matt Novak, who runs Gizmodo's Paleofuture. Novak is a self-professed time capsule nerd who has seen enough capsule disappointments to keep his hopes in check. "Time capsules are both optimistic and selfish," he tells mental_floss. "Optimistic in the sense that they represent a belief that not only will anyone find them sometime in the future, but also that anyone will care about what's inside."

Time capsules as we know them are a relatively new invention that became famous in 1939 with the burial of the Westinghouse Time Capsule at the World's Fair. Not to be opened until the year 6939, this highly publicized capsule contained both quotidian items and extensive writings on human history printed on microfilm (along with instructions on how to build a microfilm viewer). It was an ambitious project, with engineers specially designing the capsule to resist the ravages of time. Most time capsules, however, aren't equipped to be buried underground.

"Burying something is literally the worst way to preserve it for future generations," Novak says, "but we continue to do it." Contents are routinely destroyed by groundwater, so most time capsules reveal little more than trash chowder.

Still, Novak holds out hope for "rare one percenters—those time capsules that not only have something interesting inside, but also survived their journey into the future without turning into mush." The following nine time capsules, however, fall firmly in the remaining 99 percent.

1. THE PAST COMES ALIVE IN TUCSON!

In 1961, Tucson, Arizona's Campbell Plaza shopping center—the first air-conditioned strip mall in the country!—celebrated its grand opening. To make the event truly memorable, developers buried a time capsule beneath the mall, forbidding anyone from opening it for the achingly long time period of 25 years.

When 1986 finally rolled around, another celebration was held for the capsule's unearthing. Three television crews captured the moment when workers, accompanied by a former Tucson mayor, excavated the capsule and cracked it open. Archaeologist William L. Rathje was on hand, and he later reported its contents as "a faded local newspaper (in worse condition than many I’ve witnessed being excavated from the bowels of landfills) and some business cards."

2. BAY CITY'S "PEACE CAPSULE"

In 1965, workers at Dafoe Shipbuilding Co. in Bay City, Michigan buried the “John F. Kennedy Peace Capsule.” It was to remain buried for 100 years—until city council members got antsy in 2015 and ordered for it to be unearthed five decades sooner than originally intended.

When crews unsealed the giant capsule, they found it totally drenched: The shipbuilders responsible for sealing the capsule couldn't prevent it from taking on water. Many of the items were paper ephemera that didn't survive their 50-year submersion.

Non-paper items that could be identified included, according to MLive.com, “an old pair of lace-up women's boots, large ice tongs for carrying blocks of ice, a slide rule with a pencil sharpener, a pestle and wooden bowl, a centennial ribbon, a coffee grinder, a filament light bulb, an old non-electric iron and lots of Bay City Centennial plates, a 1965 Alden's Summer Catalogue, papers from Kawkawlin Community Church, and booklets from the labor council.”

3. WESTPORT ELEMENTARY'S TOO-SUCCESSFUL CAPSULE

In 1947, the superintendent of Westport Elementary School in Missouri buried a time capsule that wasn't to be opened for another 50 years. He left a note detailing this fact, but he forgot to include any information about the capsule's location. When it came time to retrieve it, no one knew where to start digging. ''We're calling it a history mystery,'' said a teacher who was tasked with finding it. She had little to go with—the school's original blueprints, like the capsule itself, were lost.

4. A TIME CAPSULE WORSE THAN GOING TO CLASS

In 2014, New York Mills Union Free School District students filed into an assembly hall to watch the opening of a 57-year-old time capsule. The capsule, buried under the school’s cornerstone, was revealed to contain "a 1957 penny, class lists, teacher handbook, budget pamphlet, and letterhead." In a video of the unearthing (via Paleofuture), you can hear stray boos from disappointed students who expected much more than letterhead.

5. NEW ZEALAND'S RARE FIND

In 1995, a 100-year-old capsule thought to contain historical documents was opened by hopeful scholars in New Zealand. According to the New York Times, "all they found was muddy water and a button.”

6. THE SMELL OF HISTORY IN LONG ISLAND

For its 350th anniversary in 2015, the residents of Smithtown in Long Island, New York opened a time capsule that had been buried in front of town hall in 1965. An unveiling celebration was held, and a crowd of more than 175 gathered to watch town officials dressed in Colonial costumes dramatically reveal its contents.

These included, according to Newsday, "a proclamation of beard-growing group Brothers of the Brush, papers and paraphernalia from the town's 300th anniversary events, a phone book, an edition of The Smithtown News, pennies from the 1950s and '60s, a man's black hat, and a white bonnet.”

Town residents and officials alike came away unimpressed. Smithtown Supervisor Patrick Vecchio said, ”I would have thought those folks would have used a little more imagination and put some artifacts from that time in the time capsule.”

Kiernan Lannon, the executive director of the town's Historical Society, told Newsday, "The most interesting thing that came out of the time capsule was the smell. It was horrible. I have smelled history before; history does not smell like that. It was the most powerfully musty smell that I've ever smelled in my life."

7. NORWAY'S ANACHRONISTIC TREASURE TROVE

The residents of Otta, Norway had been eagerly awaiting the day when they'd get to open a package that had been sealed in 1912 and given to the town's first mayor in 1920, along with a note: "May be opened in 2012." Townspeople hoped it contained oil futures, while historians optimistically predicted relics from a 400-year-old battle.

The parcel was opened at the end of a lavish ceremony that featured musical performances and speeches. The crowd, which included Princess Astrid of Norway, had to wait 90 suspenseful minutes (in addition to the 100 years since 1912) before they got down to business.

The Gudbrandsdal museum's Kjell Voldheim had the honor of opening the package. Inside he found ... another package. Inside that package were miscellaneous papers, and Voldheim narrated for the crowd as he pored through the items. “Oye yoy yoy," he said ("almost in exasperation," according to Smithsonian), as he tried to make sense of what he was seeing. Included amongst the lackluster documents were newspapers dated from 1914 and 1919, a few years after the package had presumably been sealed. While deemed authentic, the find was nonetheless quite confusing.

8. MICHIGAN'S CAPITOL MESS

The Michigan State Capitol celebrated its 100th birthday in 1979, and officials marked the occasion by opening a capsule that had been buried beneath the building's cornerstone. While the itemized list of the capsule's contents was intriguing—"1873 newspapers, a state history, a history of Free Masonry, a copy of the Declaration of Independence, a silver plate inscribed with Lansing officials’ names, and other papers on specialized topics"—it wasn't included in the actual box. The actual items that were buried wound up being destroyed.

“They’re in very bad shape,” Robert Warner, director of the University of Michigan's Bentley Historical Library, said. Water damage had ruined the fragile paper documents, and Capitol anniversary revelers had to gamely celebrate a box full of sludge.

9. KEITH URBAN'S TIME CAPSULE CONFUSION

Australia's Pioneer Village Country Music Hall had been left in disrepair, which is what made the discovery of a plaque on its grounds in 2014 so exciting. Perhaps there was promise buried beneath the abandoned venue. Hidden behind overgrown vegetation, it read:

Pioneer Village Country Music Club
10 yr Time Capsule
Placed by Mayor Yvonne Chapman
This Day 4th July 1994
To be Re-opened 4th July 2004

As recounted in Paleofuture, the capsule's opening was a decade overdue, though fans who used to frequent the music hall said they already knew what was inside: a photo of a young Keith Urban. The musician got his start at Pioneer Village, and the photo was buried to celebrate the local star.

Oddly, a different capsule from 1994 was discovered on the music hall's abandoned grounds in 2013. Keith Urban fans eagerly opened it, thinking they had found the photo, but were left disappointed when it proved to be empty. So, by process of elimination, a photo of Keith Urban had to be in the more recently discovered capsule. Unless there's a third capsule, in which case they should probably just give up and buy a Keith Urban photo on eBay.