Tony Bennett no doubt cocktailed here, and another Tony, as in Prime Minister Blair, has also been entertained inside its high glass walls: Welcome to the penthouse, make that two penthouses, developed by a godfather of modern California architecture and home to San Francisco royalty since the 1960s.

An easily recognizable tower on Green Street in Russian Hill, The Summit is sometimes called Eichler Summit for its famous developer, Joseph Eichler, who is known for countless iconic residences and buildings but just one high-rise: this one.

The 32-story, 320-foot-tall tower opened as an apartment building in 1965; in 1974, the homes were converted into condominiums. It looms large in San Francisco literary lore, having made appearances in Armistead Maupin's Tales of the City series and Sean Wilsey's Oh the Glory of It All. Wilsey has a personal connection: His parents, philanthropist Alfred Wilsey and author Pat Montandon, were the first buyers of these two properties that are now up for grabs.

Just Listed! The Crown Jewel of San Francisco's Skyline.www.youtube.com

Most recently the penthouses were home to the late, great SF couple George Shultz, a former U.S. Secretary of State, and Charlotte Mailliard Shultz, an heiress/philanthropist who also served as Chief of Protocol for the City of SF and State of California. Charlotte originally owned the north penthouse with her previous husband, real estate developer and previous owner of the local Fairmont Hotel Melvin Swig; when she and George were betrothed, they purchased the second penthouse condo, which is connected by hallways on the 32nd floor. According to the San Francisco Chronicle, the two lived in the north penthouse and kept the other for entertaining.

Both glittering penthouses are marked by floor-to-soaring-ceiling glass walls with views to match their $17 million and $12 million price tags (the units may be sold separately or together). Each also has a dramatic staircase and in-unit elevator, as well as such creature comforts as in-floor radiant heat, wraparound decking, and skylights.

The north penthouse is a modern sanctuary. The living space has a wood-burning fireplace and a wet bar, while the chef's kitchen is beautifully outfitted with granite countertops, a double Viking oven, Wolf range, two Sub-Zero refrigerators, Miele dishwashers, and a floating island. The butler's pantry has a Sub-Zero wine refrigerator, naturally. Up a curved staircase (though you can also take the elevator), is the primary suite with views from the Golden Gate Bridge to Alcatraz, along with two bathrooms, three walk-in closets, a dressing room, and private balcony.

The south tower, too, is bathed in sunlight with glorious views of the San Francisco Bay and city skyline. The grand living room sits beneath 20-foot ceilings with wood-paneled walls and floor-to-ceiling glass. A gourmet kitchen and formal dining room are prime for hosting parties. Up the pretty staircase is a mezzanine with a wet bar and wood-burning fireplace. Enjoy views of the city with friends, and then retreat to the primary suite with two walk-in closets and a marble-clad bathroom.

Building amenities include parking, a 24-hour doorman, extra storage, and an onsite manager.

These homes may be among the highest priced luxury condos in the city, but you'll know that you tread in the slippered footsteps of true San Francisco VIPs.

South PH, Unit #3202

3 Bed | 3 Bath | 2 Half Bath

4935 Sq. Ft.

Asking price: $12,000,000 (HOA monthly dues: $6,266)

North PH, Unit #3201

3 Bed | 4 Bath | 1 Half Bath

5380 Sq. Ft.

Asking price: $17,000,000 (HOA monthly dues: $7,311)

// 999 Green St. #3201 and #3202 (Russian Hill); for more information, visit thesummitpenthouses.com.