PORTLAND — Victoria Mansion’s brownstone exterior blends in with other historic buildings in Portland.

But step a few feet off Danforth Street and through the two tall, narrow wooden doors and you’re transported back in time to pre-Civil War opulence.

From now until Jan. 8, visitors will be able to enjoy holiday decorations that are part of the museum’s “12 Nights of Christmas,” the 150-year-old mansion’s 26th holiday display.

Coordinator Greg Sundik said the event, which brings in local decorators to execute the theme, has become increasingly popular over the years. He estimated that 800 people visited the mansion last weekend, which is typically a slow one.

On Saturday morning, dozens of visitors peered eagerly into rooms containing original furnishings from the mid-1880s and richly detailed marble fireplaces.

They marveled not only at the intricate details of the home, but searched out the theme for each day of Christmas.

The “Partridge in a Pear Tree” and “Two Turtle Doves” may have been easy to miss in the entry hall, which was warmly lit by a stained-glass skylight with personifications of the four seasons. But visitors had no problem finding “Three French Hens” and “Four Colly Birds” in the reception and dining rooms.

The “Nine Ladies Dancing” dominated an upstairs sitting room, while the “Eight Maids A-Milking” were aptly placed in the red bedroom, originally reserved for guests.

“During the Victorian years the term ‘to go a-milking’ was a phrase men used when asking a woman’s hand in marriage,” Dodge the Florist wrote in a description of its display. “Or to have a casual sexual encounter.”

But perhaps one of the most stunning scenes is the silvery “Seven Swans A-Swimming” in the parlor done by Harmon’s & Barton’s Flowers in Portland.

The centerpiece of swans is accented by an enormous silver Christmas tree, whose tip points to scenes from Homer’s Iliad painted on the ceiling.

The Italianate mansion, which is on the National Register of Historic Places, was originally built as a summer home for Leeds native Ruggles Sylvester Morse, who moved to New Orleans to become a successful hotelier. Morse bought two lots on Danforth Street in 1856 for only $11,000.

Original styles for rooms range from Victorian to Gothic to Islamic.

Sundik said the mansion’s original structure is largely intact. According to him, the tower was redone about 20 years ago, and the Turkish smoking room was restored about 10 years ago. The skylight in the entry hall was restored following a 1938 hurricane.

The holiday display will continue through Jan. 8, when the mansion will close until May 1. Admission to “Christmas at Victoria Mansion” is $15 for adults, $13.50 for seniors, $5 for students ages 6-17; children under 6, free. (Prices are subject to change.)

Sundik said the first 100 visitors on Thursday, Dec. 23, will receive a commemorative poster. The mansion will be open from 11:30 a.m. to 4:30 p.m. on Christmas Eve.

Sundik said this is the 26th year of decorating the mansion for the holidays. Past themes include “A Dickens Christmas,” “A Christmas Carol,” “Father Christmas” and “Three Kings.”

“Each year is a little different,” he said.

Sundik said the museum offers guided tour during its regular operating season, which runs from May 1 to Oct. 31.

Visitors admire the decorated entry hall at Victoria Mansion on Danforth Street in Portland.