A $44.5 million mansion in Aspen has a secret bedroom and passageway built for the original owner's mistress. Take a look inside.

The 22,000-square-feet Peak House is the highest residence on Aspen's "Billionaire Mountain." It's on the market for the first time in over 20 years.

• The Peak House is a famous estate in Aspen, Colorado, currently on sale for $44.5 million.
• It's the highest home in the Red Mountain neighborhood, which has been nicknamed Billionaire Mountain. 
• The 22,000-square-foot estate has unusual features like a secret passageway built for a mistress. 

At the top of Aspen's coveted neighborhood Red Mountain — nicknamed "Billionaire Mountain" thanks to its ultra-rich residents — is The Peak House Estate.

Read more: I went inside million-dollar homes on Aspen's 'Billionaire Mountain,' a residential enclave for the ultra rich

For the first time in more than 20 years, the seven-bedroom, eight-bathroom property is on the market and currently listed for $44.5 million, according to Compass.

Source: Compass 

The location of The Peak House is arguably the home's most unique feature. It's the highest residence on Red Mountain with panoramic views of downtown Aspen and its four ski slopes.

During a tour of the home, Heidi Houston, the listing agent at Compass told Insider that in addition to its height and views, "this house has the best stories."

As we walked around the home, Houston told me about the property being seized by the FBI at one point, as well as the addition of a mistress suite.

But first, let's go back to 1995, when builder Joe Zanin finished the five-year build of The Peak House, according to its listing. The European-style home, carved into Red Mountain, has rich pine paneling and heart-pine floors throughout.

Source: Compass 

In the 1990s, Aspen's building codes were much more lenient than today, Houston said. At the time, the codes allowed for this sprawling 22,000-square-foot property to be developed.

It also allowed for features like a 12-car garage and an indoor pool to be built — something few other homes on Red Mountain have, Houston said.

In 1997, financier Viktor Kozeny bought the estate for $19.7 million, which was the most expensive purchase in Aspen history at the time, according to Aspen Daily News.

Source: Aspen Daily News

While Kozeny owned the property, he hosted lavish, invite-only parties with celebrities like Natalie Cole, Ivana Trump, and blue-chip investors, according to a Fortune article from 2000. At the parties, guests would gather in the home's grand living room ...

Source: Fortune

... or pop expensive Champagne and eat caviar at one of the home's wet bars.

Source: Fortune

Kozeny owned the house until 2001. During the time he owned the home, he added his own personal touches like a wine cave, Houston said.

But his most scandalous addition was a mistress suite. Inside what is today's media room, Houston pointed out two hidden doors; one that leads to a closet, and the other to a secret hallway.

After a short walk through a hallway and bathroom, a door leads to a secret bedroom that was designed for Kozeny's mistress, Houston said.

The mistress could access the room through the garage, and Kozeny would go through the media room without anyone noticing, Houston said.

But that wasn't Kozeny's only scandal. Nicknamed the "Pirate of Prague," Kozeny swindled investors out of $180 million, according to Forbes. Today, he remains an international fugitive.

Source: Forbes

In 2001, The Peak House was seized by the FBI. The property was later sold to its current owner Rick Braddock, the former CEO of Priceline and Fresh Direct, for $22 million, according to Forbes.

Source: Forbes

Braddock and his wife Susan remodeled the home with the help of interior designer David Easton, according to Houston. They spent millions of dollars to update the property, and rooms like the kitchen were completely overhauled, Houston said.

Source: Compass 

Easton also transformed the home's outdoor spaces. He redid the terraces, added a giant compass to the patio, and remodeled the pools, Houston said.

Now, Houston is looking for the home's next owner. Houston said she imagines the buyer will want to add their personal stamp to the home.

She envisions that the future owner will want to add contemporary elements, and says a home like this won't be found anywhere else in Aspen.

"When you see a house like this, you know that it's been here a long time and that it will be here a long time," Houston said. "It was built with intention, and it was built to last."

Source: Compass