The US National Archives in DC

Huge cavernous, imposing building, constructed as part of the great plan to create new jobs to help lift the country out of depression.
Contains really interesting archives including:
- An original signing of the Magna Carta - bought by Ros Perot
- The US constitution (old and not as well preserved as the magna carta)
- memos, letters, emails of all the presidents except Clinton, Bush and of course Obama.