"...[the acustic elements of] the 1,100-year-old Maya Great Ball Court at Chichen Itza, Mexico..." whispering galleries" allows visitors to hear whispers from 460 feet away. The feature could have once allowed a king or priest to address crowds of up to 3,000 outside without a microphone..."
The History Channel "The world is coming to an end on December 21, 2012! The ancient Maya made this stunning prediction more than 2,000 years ago. Journey back to the ancient city of Chichen Itza, the hub of Maya civilization deep in the heart of Mexico's Yucatan Peninsula, to uncover the truth about this prophecy. The Maya were legendary astronomers and timekeepers--their calendar is more accurate than our own..."