Capitol riots: What happens on Capitol Hill?

Protests in Washington DC led to crowds of Trump supporters breaking in and rioting throughout the US Capitol - one of the country's most important buildings.

But what is the area surrounding the Capitol building and why is it so important?

It's the area of Washington DC - the capital city of the United States - where Congress is situated.

This is where the US government writes, debates and passes laws.

The Hill also contains several other key sites - such as the US Supreme Court and the Library of Congress - as well as office buildings where lawmakers and their staff work.

The Hill is centred around the US Capitol building - the main location protesters broke into.

This is where elected officials in the Senate and the House of Representatives sit when debating and voting on laws, making up the upper and lower chambers of Congress.

The floor of the House is also where lawmakers gather for key political events, such as the annual state of the union address, when the sitting president lays out his accomplishments and priorities going forward.

At the heart of the US Capitol building is the Rotunda, a grand circular room.

Its use is controlled by the House and Senate, and it has been the venue for presidential state funerals as well as for other prominent figures.

Construction of the US Capitol began on top of Jenkins' Hill, referred to as Capitol Hill, in 1793. It was first completed in 1800, although it's gone through several reconstructions.

President George Washington selected the surrounding area - now Washington DC - to serve as the nation's capital.

Since then, several other key buildings have been placed on the Hill to serve Congress and the Supreme Court.

The Capitol building had to be extended throughout the 1800s as the number of US states grew to accommodate the increasing numbers of senators and representatives.

Today there are 100 senators (two for each state), and 435 voting members of the House of Representatives (divided up proportionally based roughly on the size of each state).

On top of the Capitol dome is the Statue of Freedom - a helmeted female figure on a cast-iron pedestal.

"The US Capitol is more than a building - it is the embodiment of American democracy and our way of life," the US Capitol Historical Society said in a statement following the latest siege.

Joe Biden will be sworn in as the next US president on 20 January in front of the famous white domed Capitol building.