The building was originally built into a natural canyon, and as it extended they dug more into the rock. Penn buildings are usually high in the air (on mountains or in trees) or semi-underground (in canyons and dug into the sides of cliffs), with little in-between.

During an attack, an alert sounds throughout the building so that all Penn can go and be sealed in their rooms. Shields in the glass are activated. There are several bolt holes and secret passages in case the halls are compromised.