Field trips during the school year and family vacations during the summer keep Washington, D.C., crawling with kids all year long. More than any other city, perhaps, Washington is crammed with historic buildings, arts and science museums, parks, and recreational sites to interest young and old alike. Some museums, like the National Museum of Natural History and the Daughters of the American Revolution (DAR) Museum, have hands-on exhibits for children. Many more sponsor regular, usually free, family-oriented events, such as the Corcoran Gallery of Art's "Family Days" and the Folger Shakespeare Library's seasonal activities. It's worth calling or checking websites in advance for schedules from the attractions you're thinking of visiting. The fact that so many attractions are free is a boon to the family budget.

Hotels, more and more, are doing their part to make family trips affordable, too. At many lodgings, children under a certain age (usually 12) sleep free in the same room with their parents. Hotel weekend packages often offer special family rates.

Restaurants throughout the Washington area are growing increasingly family-friendly. Many provide kids' menus or charge less for children's portions. The best news, though, is that families are welcome at all sorts of restaurants these days and need no longer stick only to burger joints.

Washington, D.C., is easy to navigate with children. The Metro covers the city and it's safe. Children 4 and under ride free.

When you arrive, get your hands on a copy of the most recent Washington Post "Weekend" section, published each Friday. The section covers all possible happenings in the city, with a weekly feature, "Saturday's Child," and a column, "Carousel," devoted to children's activities.

You can find good family-oriented vacation advice on the Internet from sites like the Family Travel Network (www.familytravelnetwork.com); Family Travel Forum (tel. 888/383-6786; www.familytravelforum.com), which has as its motto "Have Family, Still Travel," and offers helpful information and travel discounts for families planning trips, for $3.95 per month or $38 annual membership; and Family Travel Files (www.thefamilytravelfiles.com), which offers an online magazine and a directory of off-the-beaten-path tours and tour operators for families.