15 things you didn't know about the vice president's official residence, where Kamala Harris and Doug Emhoff live

The vice president's official residence is located on the grounds of the United States Naval Observatory in Washington, DC, where scientists collect astronomical data for accurate navigation.

The Naval Observatory is one of the oldest scientific agencies in the US, studying the movements of planets and stars to accurately provide positioning, navigation, and timing for the Navy and Department of Defense.

Measuring 9,150 square feet, Number One Observatory Circle contains 33 rooms.

The home features six bedrooms, a dining room, a garden room, a study, and an attic.

The home belonged to the Naval Observatory's superintendent, and then its chief of naval operations, before it became the official vice presidential residence in 1974.

Vice presidents used to live in their own homes until Congress devoted funds to refurbish the home for vice presidential use.

In 1977, Walter Mondale, who served under President Jimmy Carter, became the first vice president to live there.

Charles Denyer, author of "Number One Observatory Circle," wrote that the home was still in need of upgrades when the Mondales moved in. Part of the basement floor was still dirt, faucets would spout rust-colored water, and the vice president's first shower at the residence turned cold halfway through.

Mondale's daughter, Eleanor, once called the Secret Service when she said she saw a ghost in her bedroom.

Eleanor Mondale wrote in a 1998 issue of Swing magazine that the Secret Service was less than pleased when they found out she had reported a ghost sighting, not an actual intruder.

"I was so scared, I fainted," she wrote. "Upon coming to, I phoned the Secret Service Command Post. I whispered that there was a man in my room and hung up. Minutes later, two agents busted into the room, guns drawn. When I told them the 'man' was actually a ghost, they requested that I NEVER DO THAT AGAIN!"

Vice presidents can redecorate the home according to their tastes.

Money for maintenance of the home, as well as additions or renovations, comes from private funds or donations to the Vice President's Residence Foundation, which was founded in 1991.

Dick and Lynne Cheney decorated the residence in neutral colors.

They enlisted interior designer Frank Babb Randolph to help with the transformation, according to the Washington Post.

Vice presidents have added various amenities over the years, such as a jogging track, exercise room, and horseshoe pit.

President George H.W. Bush installed a quarter-mile jogging track at the residence, and he liked it so much that he continued running there even after he became president.

The house also features a pool, which was added by Dan Quayle.

Biden told reporters in 2010 that "no can say a negative thing about Dan Quayle" because he added the pool to the vice president's residence.

"He's my favorite vice president," Biden said. "And my granddaughters love it."

Joe Biden surprised his wife, Jill, with a tree swing on the grounds of the residence for Valentine's Day in 2010.

The commemorative plaque reads "Joe loves Jill. Valentine's Day 2010."

Jill Biden added the Family Heritage Garden, where stones memorialize all the home's previous occupants and their family members, including pets.

The garden also features a bronze sculpture of the Bidens' dog Champ, who died at age 13.

The Bidens' favorite room in the home was the Solarium.

"I love to go in that room and sit on the couch and grade papers or have meetings," Jill Biden told the Washington Post in 2017. "Often they put a round table in there and we would have dinner or lunch."

When the Pences moved into the residence, Karen Pence installed a beehive to raise awareness of the declining honeybee population.

Karen Pence previously kept bees at the Indiana governor's residence, unveiling a hive there in 2014. The hive she added to the vice presidential residence in 2017 holds 20,000 bees.

"All types of pollinators, such as bees, butterflies, birds and bats, are critical to providing our nation's food, fiber, fuel, and medicine," Pence said at the unveiling.

There's also rumored to be a secure bunker underneath the residence.

When loud blasts and construction noises were heard at Number One Observatory Circle in 2002, neighbors complained and received letters that read, "Due to its sensitive nature in support of national security and homeland defense, project specific information is classified and cannot be released." The letter sparked rumors that a secure bunker was being built after the attacks of September 11, 2001.

A spokesperson for the US Navy told the BBC in 2002 that the construction was "an infrastructure and utility upgrade."

Newsweek's Eleanor Clift reported in 2009 that then-Vice President Biden revealed the existence of the bunker at an annual Gridiron Club dinner, but Biden's spokeswoman Elizabeth Alexander told Fox News that his comments were not reported accurately.

"What the vice president described in his comments was not — as some press reports have suggested — an underground facility, but rather, an upstairs workspace in the residence, which he understood was frequently used by Vice President Cheney and his aides," Alexander said. "That workspace was converted into an upstairs guestroom when the Bidens moved into the residence. There was no disclosure of classified information."

Vice presidents have more freedom of movement at their residence than presidents do in the White House.

Presidents can't just walk out of the White House whenever they want. At One Observatory Circle, though, vice presidents have more space and privacy to live normal lives.

At a CNN town hall in February, Biden likened the White House to a "gilded cage."

"The vice president's residence was totally different," he said. "You're on 80 acres, overlooking the rest of the city. And you can walk out, and there's a swimming pool. You can walk off a porch in the summer and jump in a pool, and go into work. You can ride a bicycle around and never leave the property and work out. But the White House is very different."

Kamala Harris and Doug Emhoff, who is Jewish, became the first second family to affix a mezuzah to the home.

In November 2021, the second couple put a white mezuzah — which contains a small scroll of certain Hebrew text from the Torah — on the right side of the doorway of their residence, CNN reported. 

When they affixed the object, which marks the space as sacred and holy, Emhoff's parents came to the ceremony, Harris told Vanity Fair in December 2022. "They're originally from Brooklyn, and they are exactly what you would know and expect," Harris said, adding that the family had a big Hannukah party this year. 

"My mother-in-law, Barbara, is very pleased and proud of her son," Harris said.