But there is a tunnel segment visible before you arrive at New England Medical Center outbound. It is where the OL used to veer off into the portal leading to Washington St. It's about 150 ft long, and can't be used for anything given the way construction has built up the area in the 21 years since the Southwest Corridor opened. It's cheaper to keep it than demolish the thing.

There was a sealed, abandoned station on the line for about 20 years: New England Medical Center itself. The station was built at the same time as the hospital was in the late 1960s, with the idea that it would eventually be connected to the OL when it was eventually rerouted. Undoubtably saved a ton of money later on.

You'd be hard-pressed to find that kind of foresight anymore.