Step inside the National Building Museum, and you walk into one of Washington's most amazing architectural spaces. The museum is housed in a block-long red-brick building considered a marvel of 19th-century engineering. It has been the site for many inaugural balls beginning with Grover Cleveland's shindig in 1885 (two years before construction finished).

The center of the structure, which originally housed the U.S. Pension Bureau, is a light-filled Great Hall nearly as long as a football field. It features 75-foot-high Corinthian columns, among the tallest interior columns in the world. They look like marble, but actually are made of brick -- some 70,000 bricks each -- covered with a skin of plaster and paint.

In fact, the whole building is a brickmaker's dream; the Civil War architect-engineer Montgomery C. Meigs used 15.5 million bricks for the project, which he wanted to be sure was fireproof. Meigs also insisted on a generous supply of windows and an unusual ventilation system using adjustable air ducts.

The exterior of the building, whose floor plan is based on a Renaissance palace, features a 1,200-foot-long terra-cotta frieze by Bohemian-born sculptor Caspar Buberl. This three-foot-high strip of low-relief sculpture depicts a parade of Union military troops and units.

Don't let the setting distract you from the wealth of exhibits awaiting in the galleries, which are in the first- and second-floor arcades around the Great Hall.
Color-coded banners help you find your way. The museum opened in 1985 with a mandate from Congress to celebrate and encourage America's building arts, and it's the only institution of its kind in the United States.

Curators have interpreted their mission broadly. Exhibits have explored many aspects of the urban landscape, from factories and bridges to five-and-dime stores and ghettos; they've studied parks and roads; and they've looked back into history in shows such as "World War II and the American Dream."

One permanent exhibit is about the Pension Building itself, which is owned by the General Services Administration and "rented" free to the nonprofit board that runs the museum. The museum, which attracts 200,000 visitors annually, sponsors lectures, films and other programs.

For refreshment, the High Noon Cafe offers drinks, sandwiches and other light fare. The museum shop, a must for architecture buffs, is one of the best places in Washington to find offbeat gifts, from cards, books and puzzles to bricks, blocks and designer teapots.

The museum is at the Judiciary Square Metro stop, just across the street from the National Police Memorial. For wheelchair access, use the entrances on Fourth or G streets.

-- C.J. Mills

For Kids:

Yes, this is a museum dedicated to the building trades, and older kids interested in architecture and construction may find it interesting. But the real value here, especially for smaller kids, is the colossal scale of the interior space. It's one of the few places in Washington where kids can run around and just sort of fill up space in relative safety and calm. On the outside, there's a bit of Civil War history, in the form of a frieze depicting Union military troops. One kid-friendly permanent exhibit inside is devoted to the building of Washington, including touchable models of the Capitol, the White House and other local landmarks. However, the information provided -- including in push-button question-and-answer games -- is likely to appeal largely to the 10-and-up crowd. If you have kids of that age who are interested in building history, guided tours are offered nearly continuously. Some exhibitions, like a recent one on how bridges and trusses support things, also can be intriguing to children. Two nice touches: Firehook is a great out-of-the-way spot to grab a meal or snack, and grown-ups may enjoy the stylish (but not cheap) architectural stuff in the gift shop. In short, a visit here offers a nice side trip on days when the big-draw museums are packed or it's raining outside.

-- John Kelly and Craig Stoltz

Notes: For wheelchair access, use the entrance on Fourth and G streets. Some displays are in Braille.