Stargate

The Stargate is an advanced Protoss structure. It allows for the warpring of smaller manned Protoss air units. When additional structures are built (such as the Fleet Beacon and Arbiter Tribunal) larger Protoss capital ships can be researched and constructed.

It functions similarly to a Gateway, but requires a strong warp link in order to materialize starships from high orbit or across immense distances to appear on a planet surface.

Stargates will be returning in StarCraft II in a presumably very similar role.

Upgrades

 * Plasma Shields