While the climbing wall is nominally on Basement Level 2, of necessity, it extends much higher than the Basement 2 ceiling might allow, punching up through Basement 1. Three walls of the upper portion of the climbing wall shaft consist of observation windows open to the lobby area of Basement 1. When advanced climbers are on the wall, it's not unusual for the military staff housed on Basement 1 to gather around to cheer them on, even if the climbers cannot hear them through the sound-insulated glass.

The undulating wall has several routes, each delineated by color. Red, blue, green, orange, pick your path with care. The grips are designed to challenge blue climbers most of all, while green or red are for those less skilled. 

The climbing wall is more than entertainment. The hybridized humans need to discover and develop their often unknown and experimental skills. Beyond the standard climbing routes on the wall are grips spaced in such a way that no normal human could possibly climb them.

Garik comes to realize that there might be a reason for that. It's just possible they were designed for people that are no longer normal.

We first visit the climbing wall in Book 2 of The Human-Hybrid Project, Inside the Darkness.