Musk added to the anticipation on Monday by tweeting a poster for it.
Here's everything we know so far about the giant tunnel:
The Hawthorne test tunnel is a research and development project, according to The Boring Company's website. It stretches for roughly three kilometres from the SpaceX parking lot in California.
In May, Musk posted on his (now defunct) Instagram account: "Pending final regulatory approvals, we will be offering free rides to the public in a few months."
However, the Boring Company site states that due to high demand, tours of the tunnel will be by "invitation only."
Musk tweeted in October that the tunnel would open on December 10, but was pushed back by eight days. When Musk announced the delay on Twitter, he said the new date will be "more than a tunnel opening."
Boring Company product launch on Dec 18. More than a tunnel opening. Will include modded but fully road legal autonomous transport cars & ground to tunnel car elevators.— Elon Musk (@elonmusk) December 7, 2018
Musk gave people a taste of what the tunnel will be like in a video he uploaded to Instagram in May. Musk has since deleted his Instagram account, but the video can be seen here:
The Boring Company started work on the Hawthorne tunnel in early 2017. Musk tweeted some astonishing footage of The Boring Company's enormous subterranean drill emerging in "O'Leary Station" in November.
Ars Technica reported that the station was named after a SpaceX/Boring Company employee who passed away.
A medieval watchtower has been built to accompany the tunnel. Musk tweeted in November that he was looking to hire someone to "yell insults at people in a French accent," a reference to"Monty Python and the Holy Grail."
Passers-by have tweeted pictures of a medieval-style watchtower being built, and Musk has commented describing the tower as "medieval futurism."
Musk's fondness for "Monty Python" was recently documented in a Wired deep-dive that reported Musk sometimes interrupts meetings with Tesla execs to play "Monty Python" clips.
The company axed plans to build its Sepulveda test tunnel - which would have run from a property on Sepulveda Boulevard to Washington Boulevard in Culver City - after local groups sued the city over its proposal to exempt the Boring Company from environmental reviews.
A Boring Company spokesman said the company had changed gears and was instead looking to "construct an operational tunnel at Dodger Stadium." The Boring Company also has plans to build an underground transit system between major cities called Hyperloop.
On the "Joe Rogan Experience" podcast in September, Musk described the Boring Company as a "hobby company," which started out "as a joke."
Musk also added that he couldn't be sure of the project's success. "We are going to build a tunnel, and maybe that tunnel will be successful. And maybe it won't," he said.
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