When word got out that Alex Honnold climbed Zion Canyon’s Moonlight Buttress — a pillar of vertical sandstone 100 stories tall — alone and without a rope back in 2008, many assumed it was a hoax.

After all, it was for many people the most outrageous free-solo ever claimed. And even more suspiciously, it took place on April Fool’s Day.

But the word was true. The shy, then-unknown Honnold had actually done it. While Honnold would prove his trustworthiness in the years to come, some climbers aren’t so honest. In honor of this year’s day of fools, here’s a look at six of climbing’s most famous hoaxes from around the world:

1) In 1906, American explorer Frederick Cook was celebrated on front pages nationwide for being the first to climb Denali, North America’s highest peak. But when doubts surfaced just three years later, Cook’s deception was exposed. His “summit photos” were actually taken on a tiny peak 19 miles from the top of the continent.

2) In the 1950s, Cerro Torre in Patagonia was considered an impossible summit. Yet Italian Cesare Maestri had it easy when he fabricated its first ascent in 1959. He was the only survivor. His partner, Toni Egger, fell off the mountain — along with the camera and supposed summit photos — during the descent and died.

By 1970, climbers largely doubted Maestri, who was so incensed that he returned to Cerro Torre later that year to prove himself. Again, he claimed success, but repeat ascensionists confirmed that he, again, hadn’t summited. Years later, a bitter Maestri said that he wished Cerro Torre never existed.

3) In 1990, Slovenian alpinist Tomo Cesen said he soloed the immense and oft-tried south face of Lhotse, the fourth tallest mountain in the world, in 46 hours. He was awarded sponsorship contracts, $10,000 in cash and a national medal. But his Lhotse climb was soon debunked, like many of his other important ascents, and Cesen faded into obscurity.

Tomo who?

4) More recently, in 2010, South Korean Oh Eun-Sun claimed to have become the first woman to reach the top of all 14 8,000-meter summits — a peak-bagger’s ultimate quest. But after her 2009 ascent of Kangchenjunga, the world’s third highest mountain, she provided false summit photos and she digitally doctored others. Three of her four Sherpas said Eun-Sun had turned around more than 400 feet below the top. The Korean Alpine Federation officially dismissed her claim, and just 20 days later Edurne Pasaban of Spain officially became the first woman to collect the 8,000-ers.

5) Perhaps climbing’s most compelling liar was British über-athlete Rich Simpson, whose reputation fell apart in the late 2000s. First, he said he climbed Action Directe (5.14d), one of the hardest sport routes in the world. He even produced an inspiring 26-minute video of his training, his attempts and, finally, his “success.” It’s utterly believable.

Until he couldn’t provide uncut footage of the climb when doubts arose. Nor was he willing to repeat the route. He couldn’t even say who belayed him. Once his sponsors dropped him, he boldly moved on to other sports.

He claimed a sub-four-minute mile, a sub-2:30 marathon and an undefeated amateur boxing record.

Nobody witnessed his mile times, and he never even entered the marathon where he supposedly ran his best time. He was likely undefeated in boxing, though — no record was found that he ever fought anyone!

The final, local hoax, had a groundbreaking consequence.

6) In 1959, Ray Northcutt was a bouldering fanatic with a strong competitive streak. One day in Eldorado Canyon his partner, Ron Foreman, pointed out a 70-foot crack and face traverse on the Bastille and said, “Layton Kor just free-climbed that.”

Not to be outdone, Northcutt climbed the crack until it petered out, then committed to the blank-looking traverse. He barely clung to fingertip holds, but he managed to free it, just like Kor had. Afterward, Foreman admitted that he had made up the story about Kor. His little joke had resulted in a 5.10d — America’s hardest free climb at the time.

Like everyone, climbers want to be accepted and believed in. We want to be trusted and to be trustworthy. But while deception can be a fast track to fame, it is also the downfall of fools.

Contact Chris Weidner at cweidner8@gmail.com.