The Chirp of Chichén Itzá
Clap your hands in front of the great pyramid of Chichén Itzá, and the echo comes back as the chirp of a bird.
What was reported
El Castillo, the Temple of Kukulcán at Chichén Itzá, is a stepped pyramid built by the Maya. When visitors stand at the foot of its main staircase and clap, the echo that comes back is not a clap but a descending chirp.
Some say it sounds like the call of the quetzal, a bird sacred to the Maya, and guides have long shown it off to tourists.
Explanations offered
Acoustics researchers have shown that the chirp is caused by the sound reflecting off the regular steps of the staircase, each step sending back a slightly delayed echo, which together form a falling tone. Whether the Maya designed it on purpose is debated.
- When
- Pyramid built around 900–1100 CE
- Where
- El Castillo, Chichén Itzá, Yucatán, Mexico
- Witnesses
- Visitors and acoustics researchers
- Status
- Mostly explained
Famous cases are real, widely reported events. Each file sets out what witnesses said and the explanations that have been offered, without taking a side.