Forget Mt. Everest — it's not even close to the most difficult mountains to climb, according to mountaineers

• When climbing huge mountains, height and difficulty don't always go hand in hand, mountaineers say.
• Mt. Everest may be the world's tallest peak, but it's easier to summit than other smaller mountains, like the Seven Second Summits.

Just because Mt. Everest is the world's tallest peak, that doesn't mean it's the most difficult to climb, according to three professional mountaineers.

In fact, one expert even described Everest as a "fun" and "playful" climb compared to other peaks she's summited around the world.

Mountaineers generally agree that the highest peaks on each of the seven continents — aka the Seven Summits, which include Everest, Denali, and Kilimanjaro — are easier to climb than the second highest peaks on each continent: the Seven Second Summits.

The three mountaineers shared why Everest isn't the hardest and which peaks they found most challenging in their years of climbing.

Climbing the Seven Second Summits

Don't let the name fool you — when it comes to difficulty, there's nothing secondary about the Seven Second Summits.

Only two people have successfully climbed all seven. Jenn Drummond, a retired businesswoman and mom of seven turned professional mountaineer, is one of them.

In 2023, she became the first woman to accomplish this climbing feat and said each one came with its own harrowing challenges.

Part of what makes these peaks so difficult is that they're more remote and not as commercialized as the seven highest summits, which makes getting to them its own challenge, Drummond told Business Insider.

Mt. Everest attracts hundreds of climbers each year, and is surrounded by a booming tourism industry. The spring 2023 climbing season alone generated $5.08 million in revenue for the Nepal government, the Kathmandu Post reported. That revenue helps fund people who mark trails, set up ropes, and establish camps before mountaineers even arrive at base camp.

"If I'm climbing Everest, I don't have to make decisions — if I go left or right. I just follow a rope that somebody else has set for me," she said, adding that it all makes Mt. Everest a "fun" and "playful" climb compared to the Seven Second Summits.

"When I'm climbing Mt. Logan, or I'm doing Mt. Tyree, there's no set route," Drummond said. That added mental labor significantly increases both exertion and risk. Plus, "if something goes wrong, it's only you guys there to fix it," she said.

And for the most part, they're more technically difficult to climb. Unlike the seven highest summits, some of the Seven Second Summits involve skiing and rock climbing in addition to hiking. "You're training for a variety of different skill sets," Drummond said.

Out of all the Seven Second summits, Mt. Logan was the hardest for Drummond. It's remote, there's no trail to follow, and mountaineers do most of the climb on skis, she said. She and her team had to chart their own route, constantly test the ground to make sure the snow wouldn't give way underfoot, and build igloos around their tents to help them withstand the strong, cold winds.

K2: The Savage Mountain

If you ask Garrett Madison what the hardest mountain he's climbed is, his answer won't be Mt. Everest, either.

This world-class mountaineer has summited Mt. Everest 14 times, in addition to other massive peaks like K2, Denali, and Mt. Everest's smaller but formidable neighbors, Mt. Lhotse and Mt. Nuptse.

K2 is the hardest mountain he's ever climbed, he said, and other mountaineers agree that although it's secondary to Mt. Everest in height, it's much more challenging.

"The major differences are that K2 is steeper, it's got more objective danger — rock fall, ice fall, crevasses — and the weather is more unpredictable," Alan Arnette, a Mount Everest summiter and climbing coach who writes an Everest blog, told BI.

But just because Mt. Everest is easier than K2, that doesn't mean that anyone can hike up the world's highest mountain on a whim, Arnette said.

Climbing Mt. Everest is still risky

In 2023, a record-breaking 18 climbers died attempting to summit Mt. Everest. Even with a pre-set route, established camps, and highly skilled Sherpas to guide you, summiting this mountain is still incredibly dangerous.

As a Mt. Everest summit coach, Arnette requires that his clients already have experience climbing at least 23,000 foot tall mountains, camping in harsh winter conditions, and have some basic mountaineering knowledge before he agrees to work with them. And even someone with that level of experience might need a year of training to get ready to summit, he said.

But professional mountaineers like Arnette, Drummond, and Madison go searching for even greater challenges, paving the way for others who aspire to reach the same heights. For Drummond, becoming the first woman to climb the Seven Second Summits was deeply meaningful.

"It just shows how far society has come for women to be in these places," she said.