In addition to the functional rooms, architect Ngô Viết Thụ also designed a basement area to house specialized equipment for communication to be used in case of need. There is a backup radio system for the US-Ngụy regime.

This is where the Republic of Vietnam’s President studied the situation and discussed with the generals about the military plans of the Saigon government. Maps are arranged around the room so that all the plans of the combat troops from the tactical areas can be monitored.