Some houses have special features that select buyers prize — think mudrooms, sunrooms and wine cellars. But an English-style cottage in southwest Rochester has gone viral for an unusual reason — it comes with caves.

"We were surprised by all the interest," said owner Dr. Peter Dyck, a neurologist who directs the Peripheral Nerve Research Laboratory at Mayo Clinic. "We didn't think that that was something that would attract people."

Peter and his wife, Isabelle Dyck, bought the property 34 years ago for what they describe as a song — $90,000. Built in 1926 and tucked into a hillside, the cottage served as the pump house for the up-the-hill estate of Dr. Henry Plummer, the fourth doctor hired as a partner by the clinic.

Plummer was known as "the diversified genius" of Mayo because of his many inventions, including the medical records system that he and his assistant, Mabel Root, designed and that still is in use at the world-renowned institution. He also designed his five-story, 20,000-square-foot Tudor house, which includes 10 bathrooms, nine bedrooms and a ballroom and sits on 65 acres with its own water tower.

"The original building [that is now the Dycks' home] was essentially a carriage house and a pump house to push water from a well that was 80 feet deep, which at that time was quite deep," Peter said. "Then they pumped that water up to the water tower, which sits right behind our property. Our cave connects the pipes to that water tower."

Some of the limestone from the caves was used as building material for both the water tower and the carriage house.

When the Dycks took title to the property, it needed a lot of work. They hired the late architect Gordon Gjelten, father of National Public Radio correspondent Tom Gjelten, to guide the upgrades.

Together, they expanded the footprint of the house and included a curved, floating staircase. Gjelten loved woodwork and he used it in floors and walls to add warmth to the structure.

The four-bedroom, three-bathroom house now boasts 3,000 square feet of refined finished space where the Dycks have hosted many special occasions over the years, including wedding celebrations for two of their four children.

Lovers of art and music, the Dycks have had baroque music ensembles perform at their home.

But the 3,600 square feet of caves are all most people want to talk about. They're man-made and hollowed out of the karst limestone, Isabelle said.

"Actually, one of the other reasons for the cave was open-pit beer-making," Peter said. "There was a roadhouse just 75 to 100 feet to the east of us on the old Dubuque Trail. We think the first cave was made simply to store open-pit beer."

The Dycks haven't used their caves much. The below-ground chambers have good acoustics, which would have made them an interesting venue for small concerts, especially with baroque music.

"But they're too damp," Isabelle said.

The couple has stored occasional wine bottles in the caves. And they have fretted about losing pets in them (although that never happened).

Real estate agents Julie Glass-Yares and Michael Korby said they have been fielding a lot of questions from people keenly interested in the house's most unusual feature.

One guy who was into cloud computing wondered if he could use the caves to store hard drives, Korby said. "The temperature is consistent year-round."

"Someone was interested in growing mushrooms in there," Glass-Yares said. "Or using them for wine and beer."

"Art studio space and meditation chamber," Korby chimed in. "People's thoughts are going wild."

The $550,000 listing is being handled by Julie Glass-Yares,, or 612-790-8166, and Michael Korby,, or 612-281-0095, of Edina Realty.

Rohan Preston • 612-673-4390