National Building Museum
Formerly known as the Pension Building, this immense Italian Renaissance–style structure is home to more than 200 exhibits showcasing the construction, architecture, and engineering heritage of the U.S. and Washington, D.C.
A favorite is the Building Zone, where children can complete interactive construction projects. Make sure to pop by the Great Hall, a favorite Presidential Inaugural Ball site since President Grover Cleveland's inauguration in 1885; the 1,200-foot terra cotta frieze; and the colossal 75-foot-tall columns made of over 70,000 bricks each
—they're considered to be the tallest Corinthian columns in the world.