'Power breaking,' also called Hanmadang - which means something like celebration or festival in Korean - involves breaking large amounts of wood, concrete, granite, and the like with specific hand and foot techniques. Practitioners rely on repeated resistance training and the idea that, over time, the body can adapt to stress.
Endnotes, often confused with footnotes that live at the bottom of a page, is that lump of text at the end of the book, sometimes even relegated to a tiny font size. They're often forgotten but, in nonfiction, particularly history books, can offer a fascinating footprint into the author's research, a joyful, geeky abyss.
I've often wondered if the trade-off for growing up in the relative newness and freshness of the West Coast was befuddlement when it comes to historical preservation. We don't have many old things, and we don't really know what to do with the few that are around when our default response is to compost or field burn.