Relic 1 (Battle Standard)
Close to the spot, where there is the Archivist map - jump over to the next corridor, using the rope. The Relic is among the sculptures, right past the trap in a narrow corridor.
Relic 2 (Pennon flag)
From camp Greek fires storage walk over into a smaller chamber (Northwards), Where there is a statue. In the corner of the location, find a climbing wall to a small balcony. At the end of the balcony (watch out for two traps) there is a chest with the relic.
Opposite the campfire, camp Archive Chamber.
While escaping from the location, at the moment at which you climb out of the water - the mural is on the wall in the next corridor.
to find this one, you are going to need arrow that can be driven into wood. From Geothermal Valley, go to the Flooded Archives (camp). Swim underwater left, at the fork, and use the arrow onto the wooden platform. Thanks to this, you can get to the mural (first, you need to climb and jump around, using the rope). After you find it, jump down, where you can find the Greek Fire container - this opens the door to the main chamber, near the Greek Fire storage.