OK, I couldn't help myself, two more:
1.)
Hewitt's Cove on the Weymouth/Hingham line. It's now an upscale marina with fancy condos and high-end retail, but there is a historical marker tucked-away there, near the rampway down to the MBTA ferry, attesting to how the US Navy constructed a staggering number of destroyers--something like 100 in 2 years--at Hewitt's Cove, in the early 1940s.
American destroyers won the Battle of the Atlantic and as a result rescued England. They convoyed the mechanized transports--Jeeps, most crucially--to the Soviets, such that by the time Stalin's armies were ready to launch their massive assault on Eastern Europe, they utterly crushed the German armies with devastating blitzkrieg tactics. To a very significant degree, the war in Europe was won due to the shipbuilding efforts at Hewitt's Cove. And now you can get Wahlburgers there!
2.) This one is rather gruesome, but unquestionably "Easter Egg"-style: the true Gallows Hill in Salem where all of the accused witches were hung during the 1692 witchcraft hysteria. Here's
a story describing how a memorial was finally built at the site, only in 2017.
Given the size of Downtown Salem's Witchcraft Tourism Industrial-Economy Complex, it is a rather absurd--shameful?--piece of cognitive dissonance, that presumably so few of the tourists get out to the (
very inconspicuous and tucked-away) memorial site to pay respects.
Although come to think of it, that's probably exactly how all of the abutting neighbors prefer it!