From the Back of the Pack:
Descend Into the Darkness Below
But take care to make a map as you go, because these caves could go on forever! Paizo Publishing's GameMastery line of gaming accessories continues its mantra of providing simple and elegant tools for the busy GameMaster with the newest GameMastery Map Pack release: Caverns. Inside, you'll find 18 beautiful 5" x 8" map tiles that can be combined to form a number of underground locations that could be part of any dungeon or cave network, including:
Mushroom Cavern
Lava Cave
Twisting Corridors
Monster Den
Underground River
Vast Chasm
GameMasters shouldn't waste their time scribbling out twisting caverns and gloomy caves. With GameMastery Map: Caverns, you can keep your party busy for hours, while letting you concentrate on the monsters that live there!