Callie and Arizona's Apartment

Cristina and Callie's apartment was first seen in Season 5.

Season 5
In the episode Here Comes the Flood, Izzie fears that Derek will make her move out so she approaches Alex and suggests that they both move into a new apartment she found but he says no. She approaches Cristina but Cristina misunderstands and she and Callie pay a depost for themselves. Luckily for Izzie, Meredith allows her to continue to live at her house.

Cristina and Callie moved in and were occasionally visited by Meredith, Derek, Owen and Arizona.