The Upper Gardens

The mechanism here powers the bridge and rotates them accordingly so that Kratos can reach the next mechanism and ultimately the entrance to Aphrodite's Chamber. Turn each one and double jump to the next platform until the one in the middle of the area (just before the broken one). Rotate this one twice to turn the bridge back toward the palace and double jump to the doors.

Aphrodite's Chamber

Kratos barges in on this love goddess already busy with some of her female companions. She shoos them away as Kratos approaches and tempts Kratos in to her bed. You can choose to oblige her or not. If you do, you will need to complete a…unique QTE event, and if performed to her standards . Afterwards, scavenge the room for the Phoenix Feather from the chest, some red Orbs, and Aphrodite's Garter from behind her bed. When ready, head through the revealed portal to speak to Hephaestus in the Forge.

After the cut-scene with the smith, the doorway to Tartarus opens up.