In the alternate future of the Mutant Apocalypse arc, the Oasis, also called The Green Place, is the legendary area of the world where water was plentiful and plants thrived after the world was devastated by the mutagen bomb. Many were convinced it was merely myth, but a meerkat mutant named Mira had a map to it tattooed on her arm.
The map initially was drawn up by a hermit going by the name of the Holy Chalupa, who turned out to be an aged Michelangelo. Eventually, the remnants of the entourage known as the Red Stripe Army made it to the Oasis and lived happily.