The largest homes on the market range from $5.9 million to $68.8 million, and the house with the smallest footprint on this list is 33,500 square feet.
Habitations on such a grand scale bring with them famous occupants, prominent families, renowned architects and imported special features with historic pasts.
Oh, and one of these mansions has a 5,000-square-foot closet.
"Homes of this scale are always fun to watch as they tend to require a very unique buyer," said Alison Schwartz, vice president of corporate communications for Move Inc., operator of Realtor.com. "We're looking forward to seeing who scoops these up, especially as we approach the high season for residential real estate."
In the following slides, find the largest for-sale properties currently listed on Realtor.com.
—By Colleen Kane, special to CNBC.com
Posted 24 March 2014
Price: $5.9 million
Bathrooms: 9 full, 2 half
Square Footage: 33,500
This four-story colonnaded brick mansion on Hawley Lake was built in 2001 on 10 wooded acres with a private stocked fishing stream and pond. Among its features are a grand dual staircase, elevator and indoor pool.
The living space includes two master suites and four other suites as well as two chef's kitchens, a 1,300 bottle wine cellar, balconies, an expansive patio and veranda. Other detailing includes cherry wood wet bars, granite inlays and porcelain tile floors.
Price: $23.9 million
Bathrooms: 12 full, 3 half
Square Footage: 35,000
The Bay area's House-on-the-Hill estate was built in 1932 for bank heiress Celia Tobin Clark, who was married to Charles Walker Clark, half brother of heiress Huguette Clark.
The Tudor mansion on nearly 6 acres was designed by David Adler, the esteemed Chicago-area architect who designed more than 45 country estates.
It has vintage features like the grand ballroom, a vault for the silver and 1,700 bottles of wine, and a gentleman's cloakroom with custom cupboards made to hold shaving mugs. Luxurious detailing includes triple gold-gilded moldings, parquet flooring and black and white marble parallelogram tiles.
Visitors have included presidents Richard Nixon, Gerald Ford, Ronald Reagan and George H.W. Bush, and King Hussein of Jordan and British Prime Minister Margaret Thatcher, according to a blog post on Realtor.com.
According to that post, the master sitting room's Waterford crystal chandelier has ties to early 19th century actor Edmund Kean and the library's pine shelves and detailing were done by the master carver of St. Paul's Cathedral in London.
Price: $35 million
Bedrooms: 6 bed
Bathrooms: 6 full, 8 half
Square Footage: 36,630
The French baroque chateau known as Champ d'Or, built and named for former CellStar chairman and CEO Alan Goldfield and his wife, Shirley, is the biggest of the Texan big things. It has sat vacant on the market for years with a price tag as high as $72 million.
Champ d'Or was inspired by the lavish French chateau Vaux le-Vicomte built in 1658. To that end, it has a mirrored ballroom and formal gardens.
But because this domed estate was completed in 2002, its features include a two-story walk-in closet styled after the Paris Chanel boutique, a tea room modeled after New York's Tavern on the Green, a bowling alley, a theater, racquetball court, indoor and outdoor pools, steam sauna, veranda to seat hundreds of guests, and a cedar-lined and tiled garage.
Also on the nearly 40-acre grounds are a lake, a tennis court and twin guard houses.
Price: $13.95 million
Bathrooms: 9 full, 6 half
Square Footage: 36,957
This three-winged modern mansion with a stone courtyard was designed by Rafael Viñoly, whose extensive list of credits includes Jazz at Lincoln Center and the Cleveland Museum of Art.
Built in 1999, the residence may appeal to art collectors with its numerous galleries and hallways. A tower allows for panoramic, kingly survey of the estate's 29 acres, which include a pavilion and swimming pool, poolhouse and arbor-shaded terrace.
Price: $28.8 million
Bathrooms: 9 full, 3 half
Square Footage: 38,849
Chiltern is only 22 years old but the historic inspiration drawn from English Tudor and Elizabethan country estates is obvious. Beyond those arched doorways that really date from the 15th century lies ornate carved wood panels, vaulted beamed ceilings, a theater, indoor pool and racquetball court, enclosed porch and a roof terrace with views of the Bay.
The estate's 6 acres of private parkland feature three apartments and a guest cottage, pool and tennis court, orchards, Zen and English rose gardens complete with hedge maze, waterfalls and a koi pond.
Price: $14.95 million
Bathrooms: 10 full, 7 half
Square Footage: 39,731
When the first version of the Georgian brick Colonial Bracebridge Hall was built in 1990, it wouldn't have made this list, with only 25,000 square feet.
Additional construction in 1995 brought it up to to the current size, including a domed circular event and meeting room with a slate veranda. According to the Newark Post, in years past it has drawn the attention of Michael Jackson and Green Bay Packers quarterback Brett Favre as potential buyers.
The former MBNA corporate retreat has guest suites with private entrances and parking, as well as slate and oak flooring, french doors and windows.
The 557-acre property features one mile of shoreline on the Sassafrass River with a dock, plus a pond, a barn with 10 bays and heated workshops, tennis courts, a temperature-controlled car barn, quarters for a farm manager and staff, and two rental Colonial Williamsburg-style properties.
Price: $8.5 million
Bathrooms: 7 full, 4 half
Square Footage: 47,000
This mansion has a two-story office and library befitting the profession of its owner, bestselling crime and romance author Iris Johansen. Other features include a 5,000 square foot closet, three kitchens, one of which is semi-outdoors and one which is a catering-equipped center. The mansion also includes an indoor plaza with a 21-seat cinema and cafe
The estate's 130 acres also include a three bedroom guest house and a three bedroom caretaker's cottage, a kennel and stables.
Price: $68.8 million
Square Footage: 47,182
This French limestone Palladian mansion in the gated Bradbury Estates took eight years to build and was completed in 2011. It features two master suites, a two-story library, 3-D theater, an oak-paneled elevator, hand-painted frescoes, a 2,000 bottle wine cellar and an underground shooting range.
The estate's 8 acres include an infinity edge pool, a Jacuzzi that seats 15, a pool house and guest house (both counted in the square footage total), 10 car garage, and a temperature-controlled trout pond with a two-story waterfall.
Price: $30 million
Bathrooms: 7 full, 5 half
Square Footage: 49,568
This sprawling mountain mansion was built in 2010 using imported marble and granite. The grand foyer has dual golden staircases and marble flooring. Further into the massive complex is an indoor swimming pool with slides, waterfall and dressing rooms, a trophy room, a two-lane bowling alley, a theater, a huge sauna and a basketball court/meeting room.
Beyond the porte-cochere, expansive terraces, and the heated driveway lies the 75-acre property and mountain views galore.
Price: $13.9 million
Bathrooms: 16 full, 6 half
Square Footage: 54,000
Coming in at number 1 is this monster-scale mansion in Birmingham. Built in 1997 for Larry House, the former CEO of MedPartners, it is inspired by historic French and Italian castles.
It features hand-painted frescoes, domes, coffered ceilings, an elaborate carved wood bar and equestrian facilities, among many other amenities. No word yet on whether it can be viewed from space, but the aerial view does reveal this estate has a guitar-shaped driveway.