Musk said the Gigafactory, a battery plant that will be the largest footprint building in the world, is so big it's like an "alien dreadnought."
"It's worth seeing, this is crazy, this is like an alien dreadnought — it's really nutty," he said.
He also said he regularly debates whether humans actually exist in another civilization's video game.
"I've had so many simulation discussions it's crazy. In fact, it got to the point where basically every conversation was the AI slash simulation conversation and my brother and I finally agreed that we'd ban any such conversations if we're ever in a hot tub. Because that really kills the magic," he said.
But it's a worthy debate, because it's more probable than not we are living in a simulation than actual reality, he said.
"There's a billion to one chance we're living in base reality."
You can read his argument behind thinking we are all in a simulation here.
In fact, humans should really hope we are living in some sort of simulation because things could get really ugly if not, he said.
"Arguably we should hope that that's true, because otherwise if civilization stops advancing, that may be due to some calamitous event that erases civilization. So maybe we should be hopeful that this is a simulation, because otherwise... We are either going to create simulations indistinguishable from reality or civilization ceases to exist," he said.
The Tesla CEO also said humans are "already a cyborg."
Musk said our ability to have a digital presence through email and social media gives us "super powers" like a cyborg.
"You have more power than the president of the United States had 20 years ago. You can answer any question, you can video conference with anyone, anywhere. You can send messages to millions of people instantly. Just do incredible things," he said.
What's more, though, he said we should take the whole cyborg thing even further and add a digital layer of intelligence to our brains to avoid becoming "house cats" to artificial intelligence.
"I don't love the idea of being a house cat, but what's the solution? I think one of the solutions that seems maybe the best is to add an AI layer. A third, digital layer that could work well and symbiotically" with the rest of your body, he said.
Musk also revealed that he wants to begin sending humans to Mars by 2024.
"We're establishing cargo flights to Mars that people can count on. The Earth-Mars orbital rendezvous is only every 26 months, so there'll be one in 2018; there will be another one in 2020. And I think if things go according to plan, we should be able to launch people probably in 2024 with arrival in 2025," he said.
He even shared his vision for a Martian government.
"I think most likely the form of government of Mars would be a direct democracy, not representative. So it would be people voting directly on issues. And I think that's probably better because the potential for democracy is substantially diminished," he said.
But if all that doesn't work out, Musk hinted he wouldn't mind dying on Mars.
"I think if you're going to choose a place to die, then Mars is probably not a bad choice," he said.