Over 28,000 personnel are involved in the security operation
There are just 24 hours until Donald Trump becomes the 45th president of the United States of America.
While the city is pretty quiet at the moment, protests groups and spectators prepare for the day ahead.
Over 28,000 security personnel are involved in the security operation from a variety of agencies - including Homeland Security, the Washington Police and the Secret Service.
The ceremony kicks off in earnest today, with a wreath-laying ceremony at Arlington Cemetery to commemorate fallen members of the US military.
Later on, a free concert for members of the public will take place at The Lincoln Memorial on Capitol Hill - where president-elect Trump will deliver a very short address to the crowd.
At 7.30pm, the families of both Donald Trump and Vice president-elect Mike Pence meet at Washington Union Station.
On Friday, the morning starts after a private breakfast and an 8.30am prayer service at St John's Episcopal Church close to the Blair House - the guest house of the White House.
Following that, the president-elect and the outgoing president and first lady gather for a 'coffee-date' at 9.30am, before travelling to the inauguration ceremony.
At 11.30am, before hundreds of dignitaries including former presidents' George W Bush, Bill Clinton and Jimmy Carter the inauguration begins with music and prayers from several religious leaders.
George HW Bush has sent his regrets, but well wishes. He remains in hospital with respiratory problems.
Under US Federal Law, the president must be sworn in by 12.00pm on January 20th.
Donald Trump will place his hands on two bibles and take the 35-word oath of office. He will then deliver his inaugural address.
Protests are also planned, with one group preparing already with early morning stretches:
After a special private lunch for government, the newly-appointed president will review the armed forces - before leading the inauguration parade down Pennsylvania Avenue.
There are two official inaugural balls: one at The Walter E Washington Convention Centre, as well as the Armed Services Ball, taking place at the National Building Museum.
President Trump and First Lady Melania Trump will dance at both, and he is expected to deliver remarks at all of them.