inside two other structures that make up the pyramid also known as El Castillo, or the Castle. Earlier excavations in the 1930s had already revealed one structure inside the pyramid containing a ...

Nico Declercq of Ghent University and his colleagues have shown how sound waves ricocheting around the tiered steps of the El Castillo pyramid, at the Mayan ruin of Chichén Itzá near Cancún in ...