The name OTO comes from the ancient Greek heroes Oto and Efialtis (ΏΤΟ και ΕΦΙΑΛΤΗΣ). These giant deities had the ability to move huge stones and bring them from the darkness of the earth to the light of the day. The ancient Greeks considered Oto and Efialtis as protectors of the quarrymen in the dangerous work of marble extraction.
A couple of kilometers south of the modern marble quarries of Kinidaros in Naxos lay the ancient quarries in existence since 3000 BC. Archaeological excavations around those quarries have uncovered an area where ancient Greek quarrymen worshipped their protectors, Oto and Efialtis.