Photos: Dave Portnoy bought a $42 million home in Nantucket, complete with an underground tunnel. They're becoming a thing for the rich.

• Dave Portnoy bought a $42 million waterfront home in Nantucket, The Wall Street Journal reported.
• The realtor who sold the home said it had an underground tunnel connecting a studio and guesthouse.

Dave Portnoy bought a record-setting $42 million home in Nantucket, The Wall Street Journal reported, citing people familiar with the deal.

The 1.2-acre compound is located in the Monomoy area, "on one of Nantucket's most enviable sites," according to Workshop/APD, the architecture and design firm behind it. Portnoy spent an additional $2 million on furniture and other extras that came with the home, sources told the Journal.

The sale set a residential real estate record for the island as well as the entire state of Massachusetts, according to the Nantucket Current.

Shellie Dunlap of Lee Real Estate, who sold the home, could not confirm the identity of her client or of the buyer to Insider. She did however confirm one of the more unique features of the home: an underground tunnel.

The waterfront compound, built in 2018, was designed by Andrew Kotchen, a renowned local architect and designer, Dunlap said. The tunnel connects two structures that are separate from the four-bedroom main house: a studio and a two-bedroom guesthouse.

The tunnel makes it possible to move between them without going outside. "It's a unique creative design feature," Dunlap said.

Tunnels in luxury homes aren't entirely new. In 2015, The Wall Street Journal reported tunnels were becoming more common as a unique amenity for wealthy homebuyers.

Examples of tunnels featured in other homes include an "Alice in Wonderland"-inspired tunnel that leads to a children's playroom and a 70-foot tunnel that crosses under a road to grant easier access to the beach.

"In the big markets, people who are paying cash for $3 million homes want something that no one else has," Ron Syrnyk, an interior designer who had designed a tunnel to a wine cave for a client, told the Journal at the time.

Portnoy, who was accused of sexual misconduct and lost a defamation lawsuit filed against Insider, founded the sports blog Barstool Sports in 2003. He sold it to Penn Entertainment for $551 million, before buying it back in August for $1.

Peter Engen of Lee Real Estate, who represented Portnoy in the deal, declined to provide comment when reached by Insider. Insider was unable to reach Portnoy or Barstool directly for comment.