The continent of Kalimdor is broken up into several zones, some contested, some specific to one factio. These are broken up into the three different areas of the continent:
There are a total of 4 capital cities for both Alliance and Horde players to be found on this continent. Pre-TBC, there were only three but the expansion brought the new areas of The Exodar and Azuremyst Isle, both Draenei starting areas, for Alliance players.
The entrance portals to the various battlegrounds can be accessed from the major cities but there is a specific area in Kalimdor to access the Warsong Gulch battleground in addition to those.
Originally, the whole of Azeroth was one continent named Kalimdor, with the Well of Eternity located near the center. At the conclusion of the events of the War of the Ancients, the original Well of Eternity exploded as a result of a magical overload, splitting the continent into three major new continents - Kalimdor, representing the western region, Eastern Kingdoms, representing the eastern region, and Northrend, representing the northern region. Many smaller islands were also produced, including Kezan and the Shattered Isles, located near the old Well of Eternity and the Maelstrom it produced.