Brooklyn history to be exact. The mother of one of my little guy's best friends picked a tour for her son's birthday outing of a hole in the ground, a very big hole (discovered c.1980), which turns out to be a short actual underground railroad tunnel (with steam engines at the time, c. 1840)—making it the first subway in the world according to our guide on the tour.
In fact, he discovered it as a nineteen-year-old engineering student taking a break from college. He heard about the tunnel and then researched the history and myths about it printed in various old New York newspapers since its opening (it only lasted a little over a decade before politics and greed closed it down and covered it up until it grew into this mythic place where everything from Civil War armaments were kept to gas from WWI and supposed pirates' treasure Brooklyn wharf rats hid to etc.
My son wanted me to go along so I did, thinking it was some sacrifice to please him rather than the incredible adventure it turned out to be. Not because we had to descend to the tunnel through a manhole cover in the middle of an intersection not far from The Atlantic Avenue Detention Center I knew as the Atlantic Avenue jail when I joined the service out of New York and a few of my fellow volunteers were teenagers like me who were opting for a hitch in the service as the alternative the judge offered to going to prison, after a stint in the Atlantic Avenue jail.
Anyway we climbed down an ordinary aluminum ladder into a hole in the ground maybe fifteen feet down and then walked an actual plank covering a pool out of which rocks stuck up to trip you if you weren't careful and then under a concrete beam a few feet thick that I wasn't sure I could pass beneath without scraping my back and then maybe twenty feet through dirt, piled high on each side with a brick arched ceiling close enough to touch and finally through a tiny open "doorway" (more window sized than door) and then down different sized makeshift steps (with no railing) another fifteen feet to the dirt and rock and rubble floor of the subway.
It was damp, dank, musty, and eventually very cool (cool enough that my tee shirted boy asked to borrow the hoodie I brought with me). Maybe a hundred people or so gather there and then our guide told the history of his persistence in following up on every lead to finally figure out where the tunnel was located and how to get into it (he had to crawl through what was a three foot height space and then dig the last three feet by hand to find the bricked-in entryway that had to be broken through to finally find the tunnel that was supposed to have been filled in and destroyed back in the 1850s).
I can't give you all the details he did, but his talk was full of humor and incredible facts and linkages between them that were encyclopedic in scope. That's what made the tour so fascinating and entertaining and ultimately satisfying. The encounter with this genuine Brooklyn character, who as an obsessed teenager trumped the city leaders and engineers and historians to locate and dig out and expose to the rest of the world (and there were plenty of foreigners in the group we were a part of) the first subway!
Ah the wonders of individual pursuits and the satisfaction of a curiosity that opens the world and our shared past to rigorous inspection and, at least for me, delight. I wasn't bored for a second. To find out somethings about this guy and his find, the first subway, here's a link to his ongoing project—it took him years to get the city to allow the tours etc. and to this date none of the city leaders and engineers who dismissed his claims and attempts to prove them as fantasy have climbed down into the subway to see the wonder of it.