Headquarters

The Sailor Senshi's Command Center located under the Game Center Crown.

About
At the arcade, Luna presses buttons in a sequential order on the Sailor V game, and the machine slides back to reveal a staircase underneath which leads to a highly advanced base. She explains that this is a secret base that she uses to research on the enemy. It has a powerful shield so it can't be detected. If an intruder enters an alarm will sound.