There are these long, narrow strips of granite embedded in the sidewalks of Broadway in Lower Manhattan. I’ve seen them as far south as Battery Park and as far north as the Woolworth Building. They’re spaced a few yards apart. Each of them is inscribed with some famous 20th-century person/event and a date. For months now, I’ve been dying to know why they’re there and what they’re for.
I finally posted an Ask MetaFilter thread about it this afternoon, but before someone posted the answer I wound up figuring it out by myself. It suddenly hit me that that part of Broadway is known as the Canyon of Heroes, used for ticker-tape parades. (My brother and I went to the parade for the New York Rangers after they won the Stanley Cup in 1994.) So I typed “canyon of heroes” into Google and came up with this and this. It turns out there’s a granite slab for each ticker-tape parade that has been held in Lower Manhattan since 1886.
And here (linked from one of those pages) is a list of Manhattan ticker-tape parades through 2000.