THANKSGIVING hasn't arrived yet, but the big holiday light shows are already underway. Here is a guide to the area's fantastic displays:

* Take a half-mile walk through a Garden of Lights, a display of original twinkling flower light forms at Brookside Gardens, 1800 Glenallan Ave., Wheaton. The light show is open 5:30 to 9 (last car admitted at 8:30) through Jan. 5 (Closed Christmas Eve, Christmas day and New Year's Eve). Admission is $15 per car or van on Fridays, Saturdays and Sundays; $10 on other days. Call 301-962-1453.

* The Miracle of Lights, a holiday light show that benefits the Healthy Families Fairfax program, opens Friday and runs through Jan. 4 in Bull Run Regional Park, 7700 Bull Run Dr., Centreville. The show is open from 5:30 to 10:30 every night (closed New Year's Eve). Admission is $12 per vehicle with up to 14 passengers. Take I-66 west to Exit 52, go south on Route 29 for two miles, turn left on Bull Run Post Office Road and follow signs. Call 703-709-5437.

* More than 70 holiday light creations are on display at the Symphony of Lights, Howard County General Hospital's annual fundraiser that opens Monday and runs through Jan. 5. Through Dec. 12, the 1.4-mile drive is open Sunday through Thursday from 6 to 10 and Fridays and Saturdays (and Thanksgiving evening) from 6 to 11; starting Dec. 13, the display is open nightly from 6 to 11. Admission is $12 per vehicle with up to 11 passengers. Take U.S. 29 north to Exit 18-B (Broken Land Parkway) and follow signs to Symphony Woods. Call 410-740-7666.

* A 2.5-mile drive-through route of the Winter Festival of Lights with more than 500,000 twinkling bulbs is open Nov. 29 nightly through Jan. 5 from 5 to 9:30. $5 per car or van. Free on Dec. 25. (Canned goods accepted nightly for donation to local food banks.) Watkins Regional Park, 301 Watkins Park Dr., Upper Marlboro. Call 301-699-2456.

* Take a 3.5-mile drive through the Winter Lights Festival in an enchanted forest setting, Dec. 1 through Dec. 31 (closed Christmas day) at Seneca Creek State Park, 11950 Clopper Rd., Gaithersburg. The light show is open Monday to Thursday from 6 to 9 p.m., Fridays and Saturdays from 6 to 10, Sundays 6 to 9. Admission is $10 per car. Call 301-258-6350.

* The Washington Temple of the Church of Jesus Christ of Latter-day Saints will open its annual Festival of Lights on Dec. 6 at the Temple Visitors Center, 9900 Stoneybrook Dr. in Kensington. The festival is open through Jan. 1 from 5:30 to 10 p.m.. It features more than 300,000 colorful lights on the grounds, a display of 20 beautifully decorated trees, and nightly concerts at 7 and 8. Admission is free. Call 301-587-0144.

* The Pageant of Peace begins with the lighting of the National Christmas Tree on Dec. 5 at 5 on the Ellipse, south of the White House (Metro: McPherson Square, Federal Triangle). Tickets to the opening ceremony have already been given away. The National Christmas Tree and trees representing every state and territory can be viewed from 10 a.m. to 11 p.m. daily through Jan. 1. Musical entertainment nightly from 6 to 8:30 weekdays, 4 to 8:30 weekends Dec. 6-30 (no performances on Dec. 24-25). Free. Call 202-208-1631.

The Festival of Lights at the Washington Temple of the Church of Jesus Christ of Latter-day Saints in Kensington opens Dec. 4.