Cavern-X, located in Sedona, Arizona, was originally designed by Angel to be a time capsule. In case the X-Men or all of mutantkind were wiped out, Cavern-X would stand as a moment and evidence of their existence and struggle. Cavern-X housed numerous X-Men related artifacts/replicas including several of the X-Men's original costumes, photography of the X-Men, Magneto's Helmet, Cyclops' Visor and a disembodied Sentinel head. It was seemingly destroyed by Ultimaton, returned to his anti-mutant programation by Fantomex's death, blowing-up the base with himself in an attempt to terminate X-Force.