How long is The Boring Co.’s demonstration tunnel?

Located beneath the ground in Hawthorne, Calif., is a test tunnel by The Boring Co. that demonstrates its vision for a new form of transportation in Los Angeles. CEO Elon Musk has a somewhat unexpected description of this tunnel, which he shared with the world via Twitter last week.

Accompanying a 34-second timelapse video of progression through the tunnel was Musk’s commentary that it was “disturbingly long.” Musk apparently walked the entire length of the tunnel, which is supposed to cover 2.7 miles upon completion. Perhaps he found it so long because he was walking it rather than riding in one of the high-speed cars that the company envisions operating within the tunnel.

Also according to Musk’s tweet, this particular section of the demo tunnel will be the subject of an opening party Dec. 10, after which it will be open for pedestrians and cyclists to take a ride and test it out. Hopefully they won’t be as disturbed by its length as Musk is.