As Joe Biden was sworn into office as the 46th President of the United States earlier this week, he took up residence in one of the most famous houses in the world.

It’s well known that the President lives at the White House (or 1600 Pennsylvania Avenue to give it its proper address), but where will Vice President Kamala Harris be living out her next four years?

Here is everything you need to know about the VP’s lesser known, but still just as important, address.

The US Vice President's Residence at the Naval Observatory in Washington, DC (Photo: SAUL LOEB/AFP via Getty Images)

Where does the Vice President live?

The Vice President’s official residence is Number One Observatory Circle, a property on the northeast grounds of the US Naval Observatory (USNO) in Washington, DC.

Located roughly two and a half miles from the White House, Number One was built in 1893, and was originally inhabited by the superintendent of the USNO.

In 1923, the serving chief of naval operations (CNO) liked the house so much that he took over it for himself, and Number One would serve as the residence of the CNO until 1974.

In that year, Congress authorised the building’s transformation to an official residence for the vice president.

Technically, it was only supposed to be a temporary residence for the VP, and by law the house is the "official temporary residence of the vice president of the United States.”

It would take three years for the first vice president to move in on a full time basis.

Vice President Nelson Rockefeller was the first to make use of the property, but even then, he only really used the home for entertainment, as he already had a well-secured residence nearby.

The first full time resident was Vice President Walter Mondale, who moved in for a four year stay in 1977. Since then, every vice president has resided at Number One Observatory Circle.

President Joe Biden has of course lived at Number One in the past, being Barack Obama’s VP between 2009 and 2017.

What is the house like?

The property itself is a three-story brick house, and is relatively small compared to the President’s dwellings, with just 850 m2 of floor space.

On the first floor you’ll find a dining room, garden room, living room, lounges, pantry kitchen, reception hall, sitting room, and veranda.

The second floor contains an additional bedroom, a den, a master suite, and a study.

The attic now features four bedrooms, having once been the servants' quarters, and the main kitchen is located in the basement.

What security does the house have?

It's long been rumoured that the property contains a secure underground bunker, which may be able to withstand nuclear blasts, although the exact details of Number One’s security remain shrouded in mystery.

In 2002 just over a year following the 11 September attacks neighbours of the property complained of loud blasts and construction noises, which were loud enough to shake pictures and mirrors from the walls.

Those who complained about the disruptive noise received a letter, telling them that, “due to its sensitive nature in support of national security and homeland defence, project specific information is classified and cannot be released."

In fact, in 2009, many believe Joe Biden – then vice president to Barack Obama – revealed the existence of an underground "9/11" bunker beneath the house.

Biden's press secretary tried to clear up any confusion, telling the media that Biden was not talking about an underground facility, but instead was referring to “an upstairs work space in the residence”, which Biden understood was frequently used by vice presidents before him.

Where does the vice president live? Kamala Harris will reside at Number One Observatory Circle - here's where that is