Heliopolis

According to Erimem, Ra ordered a high priest at Heliopolis to pour gallons of beer dyed with pomegranate which was used to bait Sekhmet with as a lake of "blood". When Sekhmet became stupefied by the alcohol, she was trapped in a salt, or trisilicate, spaceship. (AUDIO: The Bride of Peladon)

Behind the scenes
Though not directly stated in The Bride of Peladon, due to the Osirans' influence on ancient Egypt, Heliopolis was likely there, as it was in the real world.