Age of Strategy Forums

Stealth bunker.
Perhaps just a stealth pit or a stealth trench.
Cost 4-6
Lives 10-20
Armor 0-2, 0-2
Attack 0
A structure with a capacity of 1 and invisibility will allow you to hide infantry, as well as a scorpion cannon and an anti-air rail gun.

If no attacks from inside the structure, I approve. Otherwise its too strong for AA guns hiding.