/ Quizzes Washington, D.C. How much do you know about Washington, D.C.? by Mark Hughes Question 1 (out of 9): What is the oldest public building in Washington, D.C.? Capitol Building Supreme Court Building White House Smithsonian Castle More Quizzes from Factmonster: Try another US Quiz ! Quiz Archive ©2022 Sandbox Networks Inc. All rights reserved. Sandbox Learning is part of Sandbox & Co., a digital learning company.