7 Name: Ronald Reagan Building and International Trade Center Location: 13th and 14th Streets and Pennsylvania Avenue NW Building Stones: Exterior, Indiana limestone; interior, various granites, chunk of the Berlin Wall in the main entrance foyer (14th Street) Remarks: The Ronald Reagan Building and International Trade Center is the second largest federal building in size -- 3.1 million gross square feet. Formal opening of the building was in the spring of 1998.

8 Name: Freedom Plaza Location: 13th and 14th Streets and Pennsylvania Avenue NW Building Stones: Border, red-pink granite from Llano, Tex.; interior, L'Enfant's original plan for Washington portrayed with streets of Georgia marble, waterways of New York sandstone, and city blocks of California granite Remarks: The park was dedicated in 1980; its southwest end contains a time capsule honoring Dr. Martin Luther King, Jr. The western end has a small pool.

9 Name: National Theater Location: 1321 Pennsylvania Avenue, NW Building Stones: Exterior, Indiana limestone; interior, fossil-bearing Indiana limestone Remarks: This building was completed in 1923; four other theaters have occupied this site since 1835, making it the oldest continually operating theater in the United States.

11 Name: Museum of American History, Smithsonian Institution Location: Constitution Avenue between 12th and 14th Streets NW Building Stones: Exterior, mainly Tennessee light-pink marble; curbs and fountain steps, Minnesota pearl pink granite. Note light-red irregularly shaped feldspar crystals Remarks: Dedicated January 22, 1964, this 7-acre structure contains 50 exhibition halls that display an amazing range of items, from the flag that inspired our national anthem to Muhammad Ali's boxing gloves. Fossils can be seen in places in the interior walls.

26 Name: Department of Agriculture, North Building Location: Independence Avenue and 12th Street SW Building Stones: Central part, Georgia white Cherokee marble; wings, Vermont marble; foundation, Massachusetts granite; interior, Tennessee marble Remarks: The main administration building between the east and west wings was designed by Rankin and Kellogg of Philadelphia. The entire building has a floor space of 300,000 square feet.

27 Name: Washington Monument Location: On the Mall, Constitution Avenue and 15th Street NW Building Stones: Exterior, upper part, Cockeysville, Md., marble; lower part, Texas, Md., marble; courses in between, Lee, Mass., marble; interior backing, Seneca, Md., sandstone and Maryland crystalline rocks; foundation, Little Falls, Md., crystalline rocks Remarks: Designed by Robert Mills, who also designed the Treasury Building, the monument stands at more than 555 feet and is one of the tallest masonry structures in the world. Because of delays and complications, which included lack of money, difficulties with the original foundation, and the theft of books and records of the society that was funding and supervising the building, the construction spanned 37 years and was not completed until 1885.