Have you ever heard of the Capitol Subway system? Us neither — well, until we saw them in a YouTube video, and since we had plans to go to Washington, we organized a tour to see and ride them.
The two lines connect the Capitol with some surrounding senator buildings, transporting senators, their staff, and authorized visitors. That said, this is not a public train system, but you can organize a tour if you're interested, though it takes some time to set it up.
One of the lines has a crewed two-track system, while the other one is a computer-controlled system.
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