During your exploration of Atys, you will come across teleportation points controlled by the Kami of the Karavan. You will be able to buy tickets there that allow you to return to the same spot later on. Each ticket can only be used once. When you but a ticket, it is placed in your inventory. To use it, open the inventory using the "i" key and select the ticket.

Teleportation therefore allows you to visit places where you have been already.