The Singing Stones of Delos

The sacred island of Delos, birthplace of Apollo and Artemis, is one of the most archaeologically significant sites in the Mediterranean. The island is uninhabited — no one is permitted to sleep there — and visited only by day-trippers from Mykonos. But the few archaeologists and conservators who have received special permission to remain overnight have documented a phenomenon that none of them publicise willingly: at specific hours of the night, the marble ruins emit a tonal sound.

The sound — described variously as a low hum, a sustained chord, or "multiple voices at the same pitch" — has been recorded and analysed. One recording, made by French archaeologist Isabelle Moreau in 2004 and later shared with acoustic physicists at the CNRS, showed a complex harmonic structure at 38–42 Hz that no geological or atmospheric source adequately explains. The sound is most pronounced near the Terrace of the Lions and the base of the colossal statue of Apollo. Local sailors from Mykonos and Naxos who pass Delos at night in calm weather report the same sound carrying across the water, and refuse to anchor in Delos's harbour after dark.