Danger Cave
Located in the caverns beneath the Xavier Institute, the Danger Cave was designed by Prodigy. Utilizing hard-light hologram technology similar to the Danger Room, the Danger Cave served as a place for the New X-Men to train for combat.[1]
Later when Donald Pierce impersonated Cyclops to form the Young X-Men, they used the Danger Cave as headquarters. During this time it served as living quarters and training area.[2]