Here's something some people probably don't know. There's a tunnel that goes under the Bay Bridge Toll Plaza and a video showing that discovery has gone viral.
Mingwei Samuel, a Bay Area software engineer recently posted about the discovery on his TikTok page, which the video now has nearly 300k views on the social media app.
The viral video shows both the tunnel and the staircases that lead to the toll booths. Samuel even goes up one of them and ends up in the middle of the freeway.
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The software engineer told NBC Bay Area that he found this underground passageway by exploring OpenStreetMap online.
"And I thought, there's no way there's a tunnel here," he said. "I bike by this place time to time and there's nothing noticeable there. But then, I went to check it out and sure enough, there was just this tiny little staircase I saw."
Samuel said there are underground tunnels all over the Bay Area and he's considering showing more of them on TikTok in the future.