The New York Observer today put out the first round of speculation on the fate of heiress Huguette Clark's massive, 42-room Fifth Avenue apartment in Manhattan. The 15,000 square-foot property occupying two floors at 907 Fifth "could be the listing of the young century, the most sought-after apartment in the entire city" after its legendarily reclusive owner died last week at the age of 104. But while New York real estate agents obsess over the fate of Clark's Upper East Side digs, her two other properties have remained untouched for decades, and will likely be sold off as part of the estate. This isn't the first time speculation has turned toward the fate, and the state, of Clark's real properties, and from coverage over the years, we've gleaned a portrait of each of her holdings. Here's what we know about them.

907 Fifth Avenue, New York, NY: In addition to the conjecture of real estate agents who will compete for the listing, we got some great details from the Observer today on the home itself, which takes up the 12th floor and half the eighth. Clark and her mother originally moved into the 28-room penthouse together, but when Huguette moved out to wed in 1928, her mother Anna began expanding into the eighth floor. Huguette moved back after her divorce in 1930, and after her mother's death in 1963 she reportedly didn't leave except to check herself into a hospital room for the last 22 years of her life.

Probably nowhere else could one find a 30-foot library followed by a 40-foot drawing room followed by a 40-foot living room. "If you stood with your back to the fireplace in the library, you could see out to Central Park through the living room window that is almost 110 feet away!" [architectural historian Andrew] Alpern wrote in an email.

Apparently Clark kept all her homes spotlessly clean and well-maintained. "Neighbors say Clark maintained it to the highest standards, with near-daily cleanings even after she moved out," the Observer notes. Montana Sen. William Clark originally built a neighboring 121-room mansion for his wife Anna, who was 39 years his junior, NBC's Bob Dotson reports. "It was a high-tech marvel for 1910: Central air and electricity, powered by coal: Seven tons a day, brought in on Clark’s own personal subway line." But Anna moved into the comparatively modest apartment after his death in 1925, according to the Observer.

Bellosguardo, Santa Barbara, CA: Huguette Clark reportedly didn't visit the 21,666-square-foot mansion overlooking the ocean in Santa Barbara after the 1950s But before that, she would stay there with her family and befriended the young daughter of the caretaker of the 23-acre property. According to Dotson's report, when she was young, "she hung out with rich daredevils who drove fast cars and flew rickety planes," but she found a kindred spirit in young Barbara Dorn, "who hid in the garden ... like her." Dorn describes Clark as "very warm. Very giving."

Huguette and her mother reportedly tore down and rebuilt the house during the depression "just to give people jobs." The new building, by architect Reginald Johnson, remains today and is valued at about $100,000. Again, the Clarks' penchant for good maintenance comes out in Dotson's piece. "You had to have painters constantly painting," Dorn told him. "It's like the Golden Gate Bridge."

The blog Real Estalker did some digging in the tax records and reports that "the massive, multi-winged 2-story mansion wraps around a central courtyard where there is a reflecting pond and according to the tax man includes 9.5 bathrooms." There's also a rumor about a thwarted sale.

It's widely rumored and reported that sometime in 2008 or 2009 Miz Clark, through her attorney, rejected an offer for the property of $100,000,000 by an unnamed suitor. Many have speculated... that the eye popping offer came from Beanie Baby billionaire turned hotelier Ty Warner who already has a massive ocean front compound down the beach and just on the other side of the Santa Barbara Cemetery from Bellosguardo.

Le Beau Chateau, New Canaan, CT: Huguette Clark reportedly purchased this 52-acre estate in the Cold-War terror of 1952 "as a sort of bomb shelter," to escape New York City in the event of a nuclear attack, according to a Bill Dedman report on NBC.

A Stamford Advocate article points to The New York Times' 1938 announcement of the construction, by architects Voorhees, Gmelin and Walker of New York. "Among the unusual features: are a linen chamber, the walls of which bear glass-enclosed shelves; a chamber in the basement for the drying of draperies; air conditioning for the dining and living rooms, and chromium-plated tubes in all bathrooms for drying and warming towels." But Huguette reportedly never occupied the house, and didn't visit for some 60 years.

Real Estalker has succinct rundown, apparently based on the property's listing with Christie's auction house.

The 12,766 square foot mansion (above) includes 9 bedrooms, 9 poopers, 11 fireplaces, 13 foot ceilings, a ballroom, wine cellar, trunk room, elevator, and a walk in vault. The extensive grounds include pine forests, open meadows, a stream with waterfall, and two identical brick caretaker guest houses, each with 2 bedrooms. The property was hoisted on to the market by Miz Clark's attorney in 2005 with a price tag of $34,000,000 and is currently listed at a hugely reduced but still skin scorching $24,000,000.