The Christopher C. Kraft Jr. Mission Control Center building on the Johnson Space Center houses two very important spaces in the life of the U.S. Space Program.
The first is the current active mission control where flight controllers monitor and manage activities onboard the International Space Station. This was also the room where shuttle missions were controlled before that program ended with the landing of Shuttle Atlantis at the end of the STS-135 mission.
The other room is just one floor above ISS MCC and is where space flights in the Gemini, Apollo, and early Shuttle missions were monitored. This room is on the list of historic places and still has mission plaques that were hung on the wall by flight controllers after those early space flights.
Very prominently there is also an American flag on display that was carried to the moon on Apollo 17, the final moon landing, and then presented to mission control where it still hangs. It is said that there are also fine dust particles in the thread of the flag from the moons surface.
If you have watched any of the historic NASA footage and it showed the flight controllers working at green consoles then you have seen this room.
It was pretty amazing to visit this place for the first time.