A Purple Line train under construction. Image by the State of Maryland.

Purple Line construction is chugging along in Montgomery County, Prince George's County, and… Elmira, New York, where trains are being assembled. And while anyone can see Purple Line trackway construction just by walking around outside in Bethesda or Long Branch, it's a bit harder to get a peek inside the Elmira factory.

So thanks, official Purple Line Twitter account, for posting this awesome video from inside the factory, with several shots of partially-built Purple Line light rail trains both inside and out. Take a look!