Zone

A Zone is an area of the game. For technical reasons the world of Tyria is divided into zones connected by boundaries. Every area boundary will always have a sign next to it indicating what zone it leads to. An area boundary can be recognized by the sign or by the thin translucent white barrier that marks the beginning of the adjacent zone.

There are various types of zones:
 * Cities
 * Outposts
 * Explorable areas
 * Missions
 * Arenas

Missions, arenas, and explorable areas are instanced zones, whereas cities and outposts have districts.

To Zone
"To zone" (as a verb - as in "Everybody ready to zone in?") means to travel through a area boundary into a zone.