NSO DECORATORS' SHOW HOUSE -- Open Friday and Monday-Thursday 10 to 3, and weekends noon to 5, through Oct. 31. Explore a 13,000-square-foot residence redecorated by dozens of local designers in the annual benefit for the National Symphony Orchestra. $15 in advance, $20 at the door. Children younger than 8 not admitted. Free parking. 9121 River Rd., Potomac. 202-416-8149.
ANTIQUES SHOW -- Friday noon to 7, Saturday 11 to 6, Sunday noon to 5. Vienna Community Center, 120 Cherry St. SE. 703-255-6360.
RUMMAGE SALE -- Saturday 8 to 4. Oak Chapel United Methodist Church, 14500 Layhill Rd., Silver Spring. 301-570-8977.
CRAFTS FAIR -- Saturday 9 to 3. About 30 vendors. Sponsored by Wesley Chapel United Methodist Church at Urbana Fire Hall, 3602 Urbana Pike, Frederick. 301-662-2324.
MODEL TRAIN SHOW -- Saturday 9 to 4, Sunday 10 to 4, by the Ellicott City Scale Model Railroad Association. Operating layouts, movies, demonstrations and about 750 tables of trains and related merchandise. $6, under 12 free; family $12. Maryland State Fairgrounds, York Road at I-83, Timonium. 410-730-1036.
SCOTTISH HIGHLAND GAMES -- Saturday 9 to 5. Traditional competitions, entertainment, vendors, displays by clan societies. $10, seniors $8, ages 12 to 18 $3, younger free. Anne Arundel Fairgrounds, Route 178, Annapolis. 410-849-2849.
APPLE BUTTER FESTIVAL -- Saturday 9 to 5, Sunday noon to 5. Entertainment, crafts fair, food vendors. Outdoors at sites throughout Berkeley Springs, W.Va. 800-447-8797.
YOUTH FOR TOMORROW Country Fair -- Saturday 10 to 4. Entertainment, amusement rides, pony rides, games, live and silent auctions of goods and services, moon bounces, food vendors. $10, students 17 and under $5, preschoolers free. Youth for Tomorrow, 10105 Linton Hall Rd., Manassas. 703-631-3360.
USED BOOK SALE -- Saturday 10 to 4. West End Library, 24th and L NW. 202-724-8707.
ALEXANDRIA SEAPORT DAY -- Saturday 10 to 4. Maritime exhibits, model boat-building. Sponsored by the Alexandria Seaport Foundation at Waterfront Park, on the Potomac between King and Prince streets, Alexandria. 703-549-7078.
HOMELAND HOUSE & GARDEN Tour, Saturday and Sunday 10 to 4, tour sites in the Homeland neighborhood of North Baltimore. $20; purchase tickets at Church of the Redeemer, 5603 N. Charles St., Baltimore. 410-323-7088.
APPLE HARVEST FESTIVAL -- Saturday and Sunday 10 to 4:30. Entertainment, crafts fair, food vendors. Graves Mountain Lodge, Route 670, Syria, Va. 540-923-4231.
AUTUMN FESTIVAL -- Saturday and Sunday 10 to 5. Crafts fair, food vendors, wine tasting; concerts by Solazo, Saturday at 1, and Alkoune, Sunday at 1. Mount Airy Mansion, 8714 Rosaryville Rd., Upper Marlboro. 301-856-1954.
ORCHID SHOW -- Saturday 10 to 5, Sunday 10 to 5 and Monday 10 to 3, by the National Capital Orchid Society. Displays of blooming plants, slide shows, gardening tips. National Arboretum, 24th and R NE. 202-245-2726.
MARYLAND RENAISSANCE Festival -- through Oct. 24. Open Saturday and Sunday 10 to 7. Crafts displays, entertainment on multiple stages, food vendors and other activities at a 25-acre re-creation of a 16th-century English village. $17, seniors $15, ages 7 to 15 $8, younger free. On Crownsville Road off Route 450, Crownsville. 800-296-7304 or 410-266-7304.
MEDIEVAL FAIRE -- Saturday and Sunday 11 to 4. Living history camps from the 11th through the 15th centuries, battle reenactments, music, crafts. $5, ages 4 to 18 $2, younger free. Marietta House Museum, 5626 Bell Station Rd., Glenn Dale. 301-464-5291 (TDD: 301-699-2544).
MULTI-CULTURAL FESTIVAL -- Saturday 11 to 2. Entertainment, vendors. Temple Hills Community Center, 5300 Temple Hills Rd., Temple Hills. 301-894-6616 (TDD: 301-203-6030).
ARTS FESTIVAL -- Saturday 11 to 5. Entertainment by students, exhibits, children's games, food vendors. Duke Ellington School for the Arts, 3500 R St. NW. 202-333-2555.
ARTS FESTIVAL -- Saturday noon to 6. Entertainment, children's arts and crafts activities, storytelling, exhibits, vendors. Outdoors around Ellsworth Drive and Fenton Street, Silver Spring. 301-565-3805.
OKTOBERFEST -- Saturday noon to 7. Products from 31 local breweries and 10 restaurants, entertainment. The Village of Shirlington, 28th and South Quincy streets, Arlington. 703-578-3888.
OKTOBERFEST -- Saturday noon to 11, Sunday noon to 8. Entertainment, German foods, beers. Fifth Regiment Armory, Howard and 29th Division streets, Baltimore. $6, under 12 free. 410-665-4787.
FALL FESTIVAL -- Saturday 12:30 to 5. Flea market, country store, dinner. Christ Church, 37497 Zach Fowler Rd., Chaptico. 301-884-3451.
BENEFIT WINE-TASTING -- Saturday 7 to 9, with light fare, followed by dancing with music by the Tom Cunningham Orchestra and the Tuxedo Park Orchestra. $125 per person; dance only, $30 in advance, $35 at the door. Sponsored by the Glen Echo Park Partnership for Arts and Culture Inc. Spanish Ballroom, Glen Echo Park, 7300 MacArthur Blvd., Glen Echo. 301-320-7757.
BENEFIT ART AUCTION -- Saturday at 8, for the Council for the Arts of Herndon and the Herndon Foundation for the Cultural Arts; preview at 7. $15 per person, $25 per couple. St. Joseph's Catholic Church, 750 Peachtree Lane, Herndon. 703-689-9535.
BENEFIT GALA -- Saturday at 8, with entertainment and dancing. $45 in advance, $50 at the door, to benefit charities in Ecuador. Sponsored by the Association of Ecuadorian Women in Washington at the Organization of American States, 17th and Constitution NW. 301-674-3375.
CLASSIC BRITISH CAR SHOW -- Sunday starting at 9 a.m. Vehicle displays and competitions in 22 classes, hayrides, food vendors. Willoughby Farm, Route 702, Middleburg. 703-933-0811.
CLIFTON DAY -- Sunday 9 to 5. Entertainment, crafts fair, food vendors, pony rides, Civil War encampment. At sites throughout Clifton in Fairfax County. 703-968-0740.
BETHESDA ARTIST MARKET -- Sunday 10 to 5:30. Displays by about 30 local and regional artists. Bethesda Place Plaza, 7700 Wisconsin Ave., Bethesda. 301-215-6660.
"FIESTA DC" -- Sunday 11 to 6. A celebration of Hispanic Heritage Month, with entertainment, exhibits, children's activities, crafts fair, food vendors. Cardozo High School Stadium. 13th and Florida NW. 202-232-4393.
"A TASTE OF GREAT FALLS" -- Sunday noon to 4. Sample specialties from about 15 Great Falls area restaurants, with entertainment and crafts displays. Village Center, Route 193 at Walker Road, Great Falls. 703-759-4076 or 703-759-4155.
COLLEGE/CAREER PLANNING EXPO -- Sunday noon to 6, meet about 90 representatives of colleges and career-oriented businesses and learn about admissions, financial aid, etc. White Flint Mall, 11301 Rockville Pike, North Bethesda. 301-468-5777.
INDIAN CULTURAL EVENING -- Sunday at 5:30, music and dance by the Know India Organization. $15. Potomac Community Center, 11315 Falls Rd., Potomac. 301-983-4471.
COLUMBUS DAY CEREMONY -- Monday at 11, with remarks by dignitaries, Joint Armed Forces Honor Guard and the Marine Band. Columbus Plaza, Union Station, 50 Massachusetts Ave. NE. 202-244-6302 or 202-619-7222.
"ROASTING HOWARD" -- Monday at 8, a "roast" and celebration of Woolly Mammoth Theatre Company artistic director and co-founder Howard Shalwitz, followed by a reception. $50, to benefit the Woolly Mammoth building fund. The Lansburgh Theatre, 450 Seventh St. NW. 202-393-3939.
NAVY BIRTHDAY PARTY -- Wednesday at 11, ceremony and plaque dedication commemorating the U.S. Navy's 229th birthday anniversary, with entertainment by the Ship's Company Chantymen. Free, but reservations required. Navy Museum, Washington Navy Yard, Ninth and M SE. 202-433-6897.