Polis Massa

Polis Massa was the location of a medical facility where Padmé Amidala gave birth to her twin children, Luke Skywalker and Leia Organa, before her death.

History
Following the fall of Anakin Skywalker to the dark side of the Force, his wife Padmé Amidala was sped to the medical facility on Polis Massa to give birth to her twin children. Luke and Leia were born in 19 BBY, though their mother died in childbirth. Leia was adopted into the House of Organa on Alderaan, while Luke was hidden by Obi-Wan Kenobi to be fostered by Owen and Beru Lars on Tatooine.

Behind the scenes
"Artoobitchuary" by Rookworm erroneously states that C-3PO received his memory wipe on Polis Massa, following the events of Star Wars: Episode III Revenge of the Sith.