Traps are a common danger in dungeon environments. From gouts of white-hot flame to hails of poisoned darts, traps can serve to protect valuable treasure or stop intruders from proceeding.
The adventuring world is filled with dangers beyond dragons and ravening fiends. Hazards are location-based threats that have much in common with traps, but are usually intrinsic to their area rather than constructed.
The Paizo Blog introduced a series of special terrains that are great for making an encounter more interesting and dynamic.