It's amazing how I'd never heard the word "spelunk" before today, and now in the span of the last few hours, I've heard it multiple times in three different contexts.
And another fun bit of trivia: in the animated series “The Seven Deadly Sins”, one of the characters owns and operates a somewhat suspicious bar in a remote mountain cave.
Seems there may be a cross-culture notion of caves and sketchy bars having similar level of… ah, “shadiness”. Makes some sense, as I’m typing this out. The dark is where (both literally and figuratively) shady things go down, and it’s hard to get much darker than a cave, so “Spelunke” seems a fitting name.
I take it you don’t play video games either. Spelunky was a pretty popular Indy game back in the day. Named after, you guessed it, spelunking. I first learned the word from “Where in the world is Carmen Sandiego” back in the 90s. I had to ask my parents what it meant.
https://en.m.wikipedia.org/wiki/Frequency_illusion