In October, Elon Musk said that the Boring Company’s proof-of-concept tunnel in LA will open to the public on December 10th. Last night, he said on Twitter that the opening is still on track, and posted a video of his walk down the entire length of the tunnel.

The sped-up video takes just over 30 seconds, and shows off the two-mile-long tunnel that Musk describes as “disturbingly long.”

Construction on the tunnel began over a year ago, and extends from SpaceX’s Hawthorne, California headquarters, to an LA suburb. Since then, the Boring Company has been selected to build tunnels for Chicago and Washington DC, and has sketched out plans to build a larger network of tunnels under LA, with the aim of reducing congestion. The tunnels will theoretically use autonomous, electric skates to move anywhere from 8 to 16 people along the system’s rails at speeds anywhere from 124 mph to 155 mph.