A fenced off plot of ground in Hanover, Md. is the first concrete sign that Tesla founder Elon Musk really plans to follow through on his promise to build a hyperloop tunnel to whisk you from D.C. to New York in 29 minutes.

Gov. Larry Hogan toured the site on Thursday, and Maryland has issued a permit for Musk's "Boring Company" to start tunneling under 10 miles of state-owned land next to the Baltimore Washington Parkway.

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"It's real," said Maryland Transportation Secretary Pete Rahn.

State officials say the project is funded by Musk's company and the cost to taxpayers would be zero or close to it.

The hyperloop would shoot cars through vacuum-sealed tubes at speeds of 125 miles an hour or more. An animated video on The Boring Company's website shows cars pulling up to an elevator on the street, dropping underground on an elevator, and then zipping on cars through a network of tunnels.

Rahn said it's potentially the future of transportation, innovative, but doable with current technology.

But like a lot of things Musk, there is still plenty of mystery. Officials in DC say they've talked to Musk's representatives, but have yet to issue permits for him to continue the tunnels in the city, or pop the cars up and down on elevators in D.C.

It's still unclear where the tunnel would head after it clears the ten miles of Maryland land.

So far there's just a fence at the sight. No sign of a boring machine, or any digging at all.