Cave's Natural Acoustics Amplify A Cappella Group's Christmas Concert

The greenTONE a cappella group has been performing holiday carols at Wisconsin's Cave of the Mounds since 2010.

It's not your typical concert hall but rather an acoustical theater created by mother nature herself. Its called the Cave of the Mounds in Wisconsin — a national, natural landmark. 

"The cave atmosphere amplified everything to be even more beautiful than just in any other setting," geologist and concert attendee Cameron Batchelor said. "So it's really awesome, and it put me in the Christmas holiday spirit." 

The greenTONE a cappella group is back inside performing their holiday songs after a year off due to COVID. They've been singing carols since 2010.