Inside the presidential guest house - the 'world's most exclusive hotel' that's bigger than the White House

Blair House is the official presidential guesthouse.

It's just across the street from the White House at 1651 Pennsylvania Avenue.

Blair House was built in the 1820s as a home for Joseph Lovell, the eighth surgeon general of the US Army.

In 1836, Francis Blair, a close friend and supporter of President Andrew Jackson, bought the home for $6,500.

The US government then purchased it in 1942 while Franklin D. Roosevelt was president.

It has served as the official guesthouse for foreign dignitaries, heads of state, and visiting delegations to Washington ever since.

President Harry Truman stayed in the house for about four years during his presidency while the White House was being renovated.

In 1950, two Puerto Rican nationalists tried to assassinate Truman at the guesthouse. Police officers stopped them from entering the home, killing one and wounding the other at the scene.

Today, Blair House makes up a large complex of "four seamlessly connected townhomes", with 110 rooms total. At roughly 70,000 square feet, the complex is technically larger than the White House.

Sources: US State Department, Blair House

At Blair House, 14 guestrooms. "Each has a full bathroom, three formal dining rooms, two large conference rooms, a hot and cold kitchen overseen by an executive chef and sous chef, a fully equipped beauty salon, an exercise room, and an in-house laundry facility," according to the official Blair House website.

Source: Blair House

There are also conference rooms, a library, and many seating areas for more intimate meetings. The finishings are traditional and luxurious.

"Since Blair House isn't a hotel, the approach is to make guests feel like they're staying in a personal residence," according to an article on the property in the November 2001 edition of the US Department of State's official magazine.

Source: State Magazine

Only those who are officially invited by the president are allowed to stay there.

But an exception is made for presidents waiting to be sworn into office during the transition period.

When a former president dies, family members are also allowed to stay at the residence before the funeral.

The residence is officially managed by the State Department's Office of the Chief of Protocol. A full-time staff is responsible for cleaning and preparing the home for visitors.

Since major renovations in the 1980s, Blair House has been a frequent meeting place for bilateral negotiations and high-level talks.

Everyone from Queen Elizabeth II and King Juan Carlos of Spain, to Russian President Vladimir Putin and Israeli Prime Minister Benjamin Netanyahu have stayed there.

Visitors typically meet with a wide range of US officials at the home.

After a meeting with Chinese president Xi Jinping at the White House in 2015, Barack Obama and Xi walked to the Blair House for a private dinner.

A year later, then-Secretary of State John Kerry met with the civilian leader of Myanmar and Nobel Peace Prize winner, Aung San Suu Kyi.

When foreign dignitaries stay there, their countries' flags are flown from the residence.

Source: BlairHouse

US officials frequently hosts dinners, official receptions, and parties at the residence, too.

Although few may know about the historical significance of Blair House, it has played a unique role in American diplomacy over the years.