The Temple of Five is a special temple built on the Algae planet by the Thirteenth Tribe.
The Sacred Scrolls say that the five pentagonally-shaped pillars inside the temple were fashioned after the five priests devoted to "The One Whose Name Cannot Be [Told(?)]."
The temple is rediscovered by Galen Tyrol, who wanders off from the base camp of the Fleet's algae harvesting mission and finds himself at the temple's entrance in a nearby mountain side.
The Cylons are interested in the location as well, guided by a Hybrid's cryptic information on the location of the Eye of Jupiter, an artifact that supposedly points the way to Earth.
The Eye's location, its form or purpose has not yet been discovered by the Colonials or Cylons, although Tyrol appears to be attracted to a circular decoration located on the central spire (The Eye of Jupiter).