An Upper East Side compound connected by an underground, skylit tunnel is heading to the auction block.
The minimum bid is $10.25 million.
The property features a four-story townhouse, at 251 E. 61st St., with the tunnel leading to an attached two-story rear carriage house. Bidding ends May 31, says Paramount Realty USA’s Misha Haghani, who’s auctioning it with Compass listing broker Jaime Richichi.
Built in 1919 and gut-renovated in 2015 by TRA Studio Architecture, the brick townhouse with a limestone facade has gone on and off the market.
It asked $14.25 million in 2016, and $13.99 million last year.
For its part, the tunnel comes with some sweet perks. It has a 150-bottle wine room, elevator access, custom cork floors, closets, 10-foot-high ceilings and skylights looking up to a courtyard.
“The tunnel was excavated by hand and sits on 5-gallon pails of soil,” Haghani said. “It runs the length of the outdoor courtyard.”
At 6,047 square feet, the five-bedroom, 6½-bath townhouse stands in the Treadwell Historic District.
It boasts floor-to-ceiling and large casement windows in the front and back — along with a home theater, multiple fireplaces, hardwood floors and a landscaped roof terrace with city views.
The 1,200-square-foot carriage house features a skylit and double-height great room, a woodburning fireplace, a kitchen and dining area that opens to a courtyard, and a bedroom with a spa-like bath.
The property also comes with 10,000 square feet of available air rights, a video security system, a sound system and a back-up generator.