Mendella is an underground settlement on Shakuras. During the Aeon of Strife, the settlement was flooded when warring Overmind Broods deliberately destroyed a nearby reservoir. During more modern history, the ruins became a proving ground for promising warriors. During the Phantom invasion of Shakuras, a nest from the Overmind's Broods settled into the area, and only a combined force of all Dark Templars and the Dark Archon where able to remove the infestation.

The Aiur caverns are a giant underground system found beneath the surface of the Shakuras. It is an artificial city constructed said to be constructed by the Xel'Naga.
There are at least two ways into the caverns, a large obvious passage and a secret "back" passage.
The caverns are decorated in many ways, including ropy "swirls" which resemble vines. A "hearbeat" sound echoes in the caverns, getting louder as one approached the large crystal chamber.
The system is very large, and one can be easily lost within it. It consists of tunnels connecting nearly-identical chambers.