A lot of folks descend the stairs into the Cave of the Mounds in Blue Mounds, west of Madison, and marvel at the great acoustics.

That's one natural feature that makes the annual Caroling in the Cave Music Series so perfect for the caverns, which we dubbed one of the Seven Wonders of Wisconsin this year.

The fact that it's 50 degrees down there isn't to be ignored in early December, either.

Now, in its fifth year, Caroling in the Cave is a three-day event that is slated for Friday-Sunday, Dec. 2-4 this year.

"The sound of the music in the cave is totally unique, as you can imagine," says Cave of the Mounds General Manager Ann Wescott.

"(It's a) most heavenly experience under the earth you'll never forget," adds the Caves' Paul Krupin.

Friday kicks off with a 2 p.m. cave tour and the Phi Mu Alpha (ΦMA) Sinfonia of UW Platteville performs down under at 7 p.m.

On Saturday, there are tours from 10 a.m. until 2 p.m., including a special Fossil Fiesta Tour (which focuses on the fossils that can be found in the caves, including a 6-foot cephalopod – and performances by greenTONE a cappella at 3 and 4:30 p.m.

On Sunday, the tours run from 10 until 3 (the Fossil Fiesta returns) and Tangled Up in Blue, from UW-Madison, takes advantage of the caves' natural reverb at 4:30 p.m.

This year the event will taken on a new vibe as hundreds of candles will illuminate the main chamber during the performances.

Santa will be available for photos before and after the music, there are free crafts and activity sheets for kids all day Saturday and Sunday and kids get a free gift when they take part in a scavenger hunt.

Visitors are also encourage do to hike or snowshoe the nature trails all weekend.

"This event continues to grow every year," says Westcott. "We have had many sold out performances as well as some with space available."

Admission is $7 per person per performance, regardless of age. You can purchase tickets online in advance. There is seating for about 60 during the performances and the remainder of space is standing room only.