DC is known for its many museums.  They're often free or charge only a nominal fee. 

 

The Historical Society of Washington, DC 

The Historical Society of Washington, DC, serves the city, its residents and visitors as an educational institution that promotes knowledge of the past for better understanding of the future.

Corcoran Gallery of Art

Includes an extensive collection of American and European masterworks, ongoing exhibitions of contemporary art, and a college of art and design.

Hillwood Museum and Gardens

Features a collection of 18th- and 19th-century Russian imperial art, and 18th-century French decorative arts. The 12 acres of formal gardens and grounds are surrounded by 13 acres of woodland bordering Rock Creek Park.

Holocaust Museum

This national institution for the documentation, study, and interpretation of Holocaust history serves as this country's memorial to the millions of people murdered during the Holocaust.

 

Built to appeal to the 13 and older set, visitors are treated to keen views, much like what scientists might see on their computers or beneath microscopes. Did you know DNA samples can be found on your cell phone? Uncover this and other scientific mysteries.

Kreeger Museum

Offers a collection of modern art, spanning from the 1850s to the 1970s. The collection includes nine Monet paintings, and works by Renoir, Pissarro, Edvard Munch, and Joan Miró.

National Building Museum

Dedicated to exploring and celebrating architecture, design, engineering, construction, and urban planning.