From the back of the package...
THERE'S SOMETHING ALIVE DOWN HERE!
Why go to the trouble of using miniatures only to push them around an empty table? Paizo's GameMastery Map Pods contain full-color gridded maps for use with RPGs and miniatures games. The map cards in this set depict key encounter areas in a foul underground sewer, allowing game masters to build their own custom sewer system!
GameMastery Map Packs provide everything you need to stay a step ahead of your players. Use this product to build sewer encounters that perfectly fit your campaign. Additional map packs explore other locales of interest to fantasy gamers.