Command Bunker

Intro This is a command bunker of my own design, it functions as a military headquarters in normal use but can deploy for extreme defense in an emergency. You're the commander. It's a circular building with teeth like a nut all around the sides heavily reinforced with only one entrance at ground level normally. However when needed it screws into a shaft lined with grooves like a nut, this creates maximum friction making it nearly impossible to dig it out. When screwed down metal and concrete doors shut covering the entire shaft. There an emergency single use bonding agent that will bond the teeth on the building to the grooves of the shaft. The building has internal power supply, communications, monitoring sensors, it seemlessly directs the military in normal function and in deployed emergency. There is a mile deep several miles long emergency evac tunnel that can be instantly collapsed if breached.