IN the nation's capital, the holiday season is a wondrous time of year, filled with the glorious sights and sounds of a city in celebration -- with everyone invited. For the holiday-time visitor, the panorama visible from the steps of the United States Capitol offers one stunning introduction to the city in its holiday finery: the eye sweeps across the National Mall, highlighted by the Lincoln Memorial and Washington Monument, and, in the distance, white-pillared Arlington House atop the hill at Arlington National Cemetery in Virginia. Another good prelude to the city's delights is the nighttime vista from the Washington Monument (open until midnight), which gives a
magical view of the thousands upon thousands of lights glittering throughout the city.
From just before Christmas through New Year's, candlelight tours of the White House are available (telephone 202-426-6700 for details), and many of the museums and historic homes are also in festive dress.
For example, the National Museum of American History presents an array of Christmas trees in styles from the historic to the modern. The Woodrow Wilson House is decorated as it might have been during the 1920s, when the former president lived there in retirement. And at the Decatur House, an 1819 Federal-style townhouse, decorations on the entrance level are reminiscent of the mansion's early years, while the second floor is turned out in the elaborate high Victorian style in vogue when Gen. Edward Fitz gerald Beale lived here.
Across from the White House, the Ellipse (site of the national Christmas tree) and the National Mall host nightly choral performances, a Nativity scene, and a burning yule log, where strollers can warm chilled hands. Visitors can also enjoy Christmas trees from each state at the ``Pageant of Peace'' on the Mall. (Call 202-426-6700 for details.)
At Constitution Hall in the Daughters of the American Revolution building, the United States Army Band offers a program of music of the season (telephone 202-692-7219 for details), and at the United States Botanical Gardens, the Christmas Greens Show, staged by the National Capital Area Federation of Garden Clubs, displays tree ornaments, wreathes, and table and hearth decorations.
Poinsettia lovers can revel in the sight of more than 3,000 of the traditional red, white, and pink flowers at the 39th annual Poinsettia Show where the blooms are arranged amid festive decorations, unusual wreathes, and a 25-foot tree (call 202-225-7099).
The holiday gala climaxes on New Year's Eve, when the Old Post Office Pavilion offers free top-name entertainment, ballroom dancing, and special menus at each of its many restaurants. Visitors can also join the countdown to midnight, when, not to be outdone by New York's Times Square, this historic building drops a giant stamp from its clock tower.
And only a short drive from downtown Washington, the gleaming white Mormon Temple in Kensington, Md., features a spectacular month-long show -- ``The Festival of Music and Lights'' -- with evening concerts presented against a background of more than 40,000 tiny lights sparkling on the trees and shrubs. (Call 301-587-0144 for details.) Practical information
For a complete listing of holiday festivities, write or call the Washington Convention and Visitors Association (1575 ``I'' Street NW, Washington, D.C. 20005; telephone 202-789-7000).
A free listing of places to stay in the city is available from the Hotel Association of Washington (1219 Connecticut Avenue NW, Suite 300, Washington, D.C. 20030).