What's DoingSPORTS CARD SHOW -- Saturday 10 to 4. $2. Westpark Hotel, 8401 Westpark Dr., McLean. 301-990-4929.

MODEL TRAIN SHOW -- Saturday and Sunday 10 to 4. Operating layouts, hobby clinics, dealer tables. $7, ages 6 to 12 $2, younger free. Dulles Expo Center, Willard Road off Route 28, Chantilly. 703-378-0910 or 410-795-7448.

COMIC BOOK/NON-SPORTS CARD Show -- Sunday 11 to 4. $2.50, under 7 free. Best Western Inn, 15101 Sweitzer Lane, Laurel. 410-569-8357.

For the Holidays COUNTRY CHURCH TOUR -- Friday 2 to 8, visit small churches in the I-270 corridor in Montgomery and Frederick counties. 301-662-5769.

MOUNT VERNON -- The former home of George Washington is open from 9 to 4 daily. Regular tours of the mansion, decorated for the holidays, are held through Jan. 6. Adults $9, seniors $8.50, ages 6 through 11 $4.50, under 6 free. At the south end of the George Washington Parkway, eight miles south of Alexandria. 703-780-2000.

CEDAR HILL -- Open from 9 to 4 daily, through Tuesday. Visit the home of Frederick Douglass, decorated with Victorian trimmings. 1411 W St. SE. 202-426-5961.

OATLANDS PLANTATION -- Open 10 to 4 weekdays and Saturdays, 1 to 4:30 Sundays through Monday. Visit the historic 19th-century plantation, decorated for the holidays. $8, $7 for seniors and students, $1 for ages 5 to 11 (younger free). On U.S. 15 six miles south of Leesburg. 703-777-3174.

U.S. BOTANIC GARDEN Conservatory -- Open 10 to 5 daily, through Jan. 5. Conservatory offers a fantasy land with a Chocolate Chunk Mountain, Cotton Candy Corner, Candy Cane Forest, a model train display, holiday greenery and more. 100 Maryland Ave. SW. 202-225-8333.

HOLIDAY TOURS -- Open noon to 4 daily except Monday, through Jan. 5. Beall-Dawson House, 103 W. Montgomery Ave., Rockville, $3, $2 seniors and students, free for ages 5 and younger. 301-762-1492.

"GARDEN OF LIGHTS" -- Open nightly except New Year's Eve from 5:30 to 8:30. Take a half-mile walk through a display of twinkling flower light forms. Brookside Gardens, Wheaton. $15 per car or van on Fridays, Saturdays and Sundays, $10 on other days. 301-962-1453.

"MIRACLE OF LIGHTS" -- Open nightly 5:30 to 10:30, except New Year's Eve, through Jan. 4. Tour a holiday light show that benefits the Healthy Families Fairfax program. $12 per vehicle with up to 14 passengers. Bull Run Regional Park, 7700 Bull Run Dr., Centreville. 703-709-5437.

"SYMPHONY OF LIGHTS" -- Open nightly from 6 to 11 through Jan. 5. Tour more than 70 holiday light creations at Howard County General Hospital's annual fundraiser. $12 per vehicle with up to 11 passengers. In Symphony Woods, on Little Patuxent Parkway off U.S. 29, Columbia. 410-740-7666.

"FESTIVAL OF LIGHTS" -- Open nightly through Jan. 5 from 5 to 9:30. Tour a 2.5-mile drive-through route of holiday lighting displays. $5 per car or van. Free on Wednesday. Canned goods accepted nightly for donation to local food banks. Watkins Regional Park, 301 Watkins Park Dr., Upper Marlboro. 301-699-2456 (TDD: 301-454-1493).

WOODLAWN PLANTATION TOURS -- Sunday; tours begin between 5:30 to 8. See how the holidays were celebrated during the Federal period. $15, $5 for children through age 18. 9000 Richmond Hwy., Mount Vernon. 703-780-4000, Ext. 27.

"WINTER AT RIVERSDALE" -- Friday from 7 to 9 p.m., music, costumed interpreters, refreshments. $5, under 12 free. Riversdale House Museum, 4811 Riverdale Road, Riverdale Park. 301-864-0420.