The Dance Floor is a location in Luigi's Mansion 3. It is found on the fourteenth floor of The Last Resort, The Dance Hall. It is one of the only two rooms on this floor, the other being the Elevator Hall. DJ Phantasmagloria is fought here. The white, red, and blue gems can be found here.
When Luigi first enters the dance floor, he sees the fifteenth floor elevator button lying in the center of the room. When he tries to pick it up, a sudden blast of sound comes from the speakers, knocking him backward and causing him to drop the button. DJ Phantasmagloria then reveals herself, along with many hoodie-wearing Goobs. After Luigi identifies and captures the one in possession of the elevator button, DJ Phantasmagloria takes it. After defeating her, Luigi gets the elevator button to the Master Suite.
Aside from a disco-themed dance floor, there are large speakers in back, a lit-up disco ball, and a disco booth for DJ Phantasmagloria. To the left and right are tables and booths.
After defeating DJ Phantasmagloria, Luigi and Gooigi can each stand on one of the unlit tiles on the dance floor, revealing a socket for the Super Suction. Luigi can use the Super Suction to suck up the disco booth, disco ball, and speakers to reveal a hidden room with records and mannequin heads wearing red afros. There is a green light in one of the records on the wall Luigi can flash with the Strobulb to activate the stairs on both sides of the room, allowing him to get both the white and red gems.
To get the red gem, Luigi and Gooigi must each spin one of the records on the left and right sides of the room to drop the disco ball, breaking it open to reveal the gem.
To get the blue gem, Luigi must use the Dark-Light Device on the mannequin head in the hidden room without an afro. Doing this reveals an afro, which he must then vacuum off the mannequin to reveal the gem underneath.