This historic carriage house built on a farm once owned by American poet (and real estate mogul) Clement Clarke Moore, who wrote “The Night Before Christmas” in 1823, is on the market for $13.8 million — down from its $15.8 million ask last year.

The 9,200-square-foot, 25-foot-wide townhouse at 313 W. 20th St. features eight bedrooms, 3½ bathrooms and details like a roof deck, a backyard garden, skylights, crown moldings, original hardwood floors, decorative fireplaces with marble mantels, lots of exposed brick and a finished cellar with a gym, sauna and studio space.

For now, it’s configured as a six-bedroom, 2½-bathroom, four-story owner’s unit, plus cellar, with double height entertaining space.

There’s also a two-bedroom rental unit with a windowed kitchen, skylights and a private rooftop.

The co-listing brokers are Scott Fava, of Nest Seekers International, Ryan Serhant  and Douglas Elliman’s Hunie Kwon, Grace Steel, Fredrik Eklund and John Gomes.