Elon Musk gave us a hypnotic look at his Boring Company's test tunnel under the Los Angeles area over the weekend.

The entrepreneur, who also heads Tesla and SpaceX, tweeted Saturday about traversing his underground transit "loop."

"Walked full length of Boring Co tunnel under LA tonight. Disturbingly long. On track for opening party Dec 10. Will be very one-dimensional," he tweeted, referencing one of his "dad jokes" from last week's Recode Decode interview.

Musk also posted a video that takes us through the tunnel, which lies beneath the Hawthorne, California, headquarters of SpaceX. When complete, the test tunnel is expected to run for 2 miles.

The loop concept features a large "skate" carrying a vehicle under Los Angeles traffic at speeds up to 155 mph (250 kph). The Boring Company has a contract to build a loop to O'Hare International Airport in Chicago.

You'll be able to try out the test tunnel after the Dec. 10 event. Musk promised free public rides on Dec. 11.