The neoclassical building, finished in 1935, houses the Supreme Court of the United States (the highest federal court). It was designed by Cass Gilbert, who also designed e.g. the Woolworth Building.
The marble used for the construction and decoration of the Supreme Court comes from various places across the USA (Vermont, Georgia and Alabama) but also Europe (Spain and Italy).
If you plan to visit the building be prepared for strict security checks and rules that you will need to follow (the whole building is a non-smoking area, no pictures or video can be taken inside it and quiet behaviour is expected since the building is an active office).
There are various exhibitions installed inside and there are the Courtroom Lectures organised but only when the Court is no longer in session for the day. You can check the calendar on the official website where the lectures are planned. There are no entry fees, and the building is closed during the federal holidays.
There are periodically changing exhibitions inside.
Courtroom Lectures:
Mon - Fri: On days that the Court is not sitting, the lectures are generally scheduled from 9:30 am to 3:30 pm. Otherwise they are only available after the Court adjourns for the day.
Free admission.
Wikipedia https://en.wikipedia.org/wiki/United_States_Supreme_Court_Building
Official website http://www.supremecourt.gov/
Phone +1 202 479 3030
Address 1 First St NE, Washington, DC 20543, USA
Coordinates 38°53'26.251" N -77°0'15.981" E