If you enter the PHAROS, TEMPLE OF ISIS level only to find you are missing one of these key artifacts, it's possible to return to the earlier levels to get them. From the submerged ruins with the receptacles for these artifacts, swim up to the opening in the cavern ceiling.

Climb out on the small ledge.

Crawl through the low, dark opening...

...turn around, drop onto the ramp below...

...and slide back into the COASTAL RUINS.

You splash down in the tide pool northeast of the ruins. This exit from the PHAROS, TEMPLE OF ISIS level is marked G on the map of the ruins. Swim forward (south) and around the rocks to the building ahead on the right.

Climb out of the water here. This is door C on the map of the ruins.

Go up the stairs and through the gate. Then climb down the ladder and follow the passageway back to the TEMPLE OF POSEIDON.

NOTE: If you didn't open this gate earlier from the other side, see this separate page for an alternate route.

When you re-enter the TEMPLE OF POSEIDON through gate C, you'll climb the ladder to the ROOM WITH FOUR SMALL POOLS AND FACE MOSAIC ON FLOOR, where you found the LEFT GAUNTLET of the ARMOR OF HORUS earlier.

Enter the room to the right (west).

Go through either of the small doors flanking the sarcophagus.

Follow the passageway around the next corner. There's a raised crawlspace about halfway along the west wall. Climb into it.

Crawl through, and continue to the LOST LIBRARY.

If you have not yet completed the LOST LIBRARY and HALL OF DEMETRIUS, follow the walkthrough for that level from the beginning to get the PHAROS PILLAR. Then continue to the next level, HALL OF DEMETRIUS to get the PHAROS KNOT.

If you have completed the LOST LIBRARY and HALL OF DEMETRIUS but missed the PHAROS PILLAR, check the section near the end of the LOST LIBRARY walkthrough on returning to the upper level in order to find the artifact. Then retrace the route shown above to return through the crawlspace back to the TEMPLE OF POSEIDON and through gate C and return to the COASTAL RUINS.

If you have completed the LOST LIBRARY and HALL OF DEMETRIUS but missed the PHAROS KNOT, go through the big doors at the east end of the main hall in the the LOST LIBRARY (shown in the screenshot above) to re-enter the HALL OF DEMETRIUS. Follow the DEMETRIUS walkthrough to find the artifact and exit back to the COASTAL RUINS.

Once you have both artifacts, re-enter PHAROS TEMPLE OF ISIS through the underwater passageway at F on the map of the ruins.

[Pharos Walkthrough]