In front of the Starbucks at the Washington Grand Hyatt 1000 H St NW.

Day tours start at 9:00 AM and end at 1:00 PM.
Night tours start at 7:00 PM and end at 10:00 PM. Please

Arrive 10 Minutes before the tour.

Here is a link to a local garage.
https://quikparkinc.com/lots/1001-g-st-nw/