Rock climber Alex Honnold left his viewers speechless and mildly nauseated, as he scaled 3,000 feet up the side of El Capitan mountain in Yosemite National Park, all without a single rope or harness. Unfortunately, this is the same mountain where two climbers died after falling to their deaths, last summer. According to Daily Mail, Alex Honnold, 33, is from California and the only person who has fully climbed El Capitan without any assistance.

Although for Alex Honnold, "Free Solo" has been released for six months, the National Geographic documentary aired for the first time on Channel 4, May 23.

And the entire time, Honnold sent viewers into an on-the-edge-of-their-seat frenzy. Viewers were basically drenched in sweat while watching Alex make his "free solo" journey up El Capitan. With no rope or harness to secure him, one mistake could've cost Honnold his life.

"Free solo climbing is an extreme technique practiced only by the most experienced climbers who scale mountains with their bare hands, and many die trying," Daily Mail mentions in its report regarding Alex Honnold.

Reportedly, Honnold was accompanied by a filming team. His crew wasn't about that life — if you will — and definitely used the proper equipment to better ensure their survival on the mountainside. Included in the team's arsenal were a drone and two fixed cameras; they were used in scenes too difficult (dangerous) for camera operators.

What was Alex Honnold grabbing??

According to Daily Mail, there were certain spots along the mountain climb where the rock was basically smooth. The source says Alex Honnold would essentially have nothing, "seemingly invisible bumps," on the mountain's surface to grip and grapple himself upward. Reportedly, there were even times that Alex would work his fingers into a small crack because that's all that was available.

Daily Mail Online mentions that during his training, Alex Honnold worked with a rope while learning the maneuvers. Eventually, Honnold began to execute the moves perfectly. There were times when even the camera crew had to look away because they thought Alex was about to fall to his assured death below. However, he never did, and Honnold made it to the mountain's summit.

And as it turns out, Honnold said he knows what it is to be afraid. "I'm afraid of death, I'm afraid of danger, I'm afraid of pain," Alex mentions to Agence France-Presse (AFP).

"I used to be very afraid of public speaking." So, this is quite a far cry from talking about it. According to Daily Mail, Honnold has trained for this moment for over 10 years. And given all the preparation that went into the final day, it pretty much de-sensitized him to the dangers associated with the climb. With that in mind, he was able to solely focus on his objective.