The Oasis is located in the southwest of the Calico Desert. To get there the player must have fixed the bus by completing the Vault bundle at the Community Center or through Joja Mart. A ticket for the bus costs 500g.
The Oasis is run by the NPC Sandy, who sells rare seeds and other specialty items.
In back corner of the shop, there is a doorway and an NPC called Bouncer. Bouncer will block the doorway until you get the club card by completing the Mr. Qi's quests.