When you're a GM, it can be difficult to come up with literally everything possible in the entire world at any given moment your players ask for it. Even the best improvisers will sometimes be at a lack for anything truly interesting, so they just go with, "eh, you don't see anything." Kinda dull. That's where Dungeon Discoveries card decks come in from LoreSmyth. They're up on Kickstarter now and aimed at adding all sorts of interesting details to your games.