Trophonius

[4] Alternatively, according to Pausanias they built a treasure chamber (with a secret entrance only they knew about) for King Hyrieus of Boeotia.

Apollonius of Tyana, a legendary wise man and seer of Late Antiquity, once visited the shrine and found that, when it came to philosophy, Trophonius was a proponent of sound Pythagorean doctrines.

Plutarch's De Genio Socratis relates an elaborate dream-vision concerning the cosmos and the afterlife that was supposedly received at Trophonius' oracle.

He would then sacrifice, by day, to a series of gods, including Cronus, Apollo, Zeus the king, Hera the Charioteer, and Demeter-Europa.

At night, he would cast a ram into a pit sacred to Agamedes, drink from two rivers called Lethe and Mnemosyne, and then descend into a cave.

Trophonios has been of interest to classical scholars because the rivers of Lethe and Mnemosyne have close parallels with the Myth of Er at the end of Plato's Republic, with a series of Orphic funerary inscriptions on gold leaves, and with several passages about Memory and forgetting in Hesiod's Theogony.

The philosopher Friedrich Nietzsche makes a reference to "Trophonius" in the preface to his Daybreak, alluding to his labor in the "underground" of moral prejudices.