There are actually a number of lighthouses in Boston Harbor. Historically, there had been many more. Some are described at the National Park Service website: https://www.nps.gov/boha/learn/historyculture/lighthouses.ht...

Not all of these are "lighthouses", per se. Nixes Mate is actually just a concrete-and-paint reflector: https://en.wikipedia.org/wiki/Nixes_Mate

Right, Boston proper doesn't have any lighthouses actually. This one is technically in Hull, MA. It's the lighthouse for Boston Harbor, and it's also the first lighthouse built in the US. The first tower on the site was built in 1716, though as the article says, that was torn down by the patriots, rebuilt and then blown up by the British in the revolutionary war. This one was built after the war in 1783.

It's been kind of a fantasy for me to live in this lighthouse, I'm very tempted to apply for the job. Too bad it's not possible to live there anymore.