The control tower is International Underground's primary base of operations. Millie works here, keeping an eye on the trains and making sure everything runs smoothly.
The control tower is accessed via a staircase situated on the platform of International Underground Station.
Stationed in the centre of the control tower is the control board which tracks the trains' whereabouts and their progress. It is used manually, but can be set to run on automatic for a period of time when nobody is able to man the control board. A computer is also stationed nearby to write up reports and timetables. Other items in the control tower include a water cooler and a sofa, as well as a trophy awarded to the Underground that's displayed on top of a filing cabinet. A first-aid kit and fire extinguisher are hung up on the wall for easy access in case of emergency.
To the back, there is a kitchen, where Millie once cooked a meal for French chef Marcel Le Magnifique.