Tikal was the largest city of the ancient Mayan civilization and is probably Guatemala’s most famous tourist destination. If you stand at the bottom of the pyramid’s steps and clap your hands you get this incredible chirping sound. Echoes off buildings are common, but not ones that distort sound like. Whether the pyramid was constructed to deliberately make this noise, or it happened by chance, is still a matter of debate among scientists and archaeologists. Reflections from the treads of the staircase are responsible for the echo; the sound is like a bird chirping because the step height gradually changes: causing the frequency of the echo to rapidly drop.