THROUGH December 20, weekend visitors to Leesburg's historic downtown district will find their paths aglow with hundreds of luminaria, those fat white candles in sand-bottomed greased paper bags whose origins hail from the Spain of centuries past. Another centuries-old tradition, the wassail bowl, will be included in the free refreshments many Leesburg merchants will offer to shoppers to complement the scent of Christmas greens fronting all the shops.

Sponsored by the Downtown Business Association for several decades, Leesburg's "Old Fashioned Christmas" includes Santa Claus and his wife, who will stroll in and out of the shops of the district, including those in Market Station, to take last-minute orders from good little boys and girls tagging along with their parents on the Saturdays and Sundays before Christmas.

Strolling musicians (presented by the Bluemont Concert Series) also will sing and play the music of the season on Saturdays and Sundays. Some entertainers, including a clown, local choirs, dancers and mimes, will perform indoors at Market Station, the collection of restored historic buildings transformed into shops, restaurants and boutiques two blocks from King Street. From 10 to 5 December 12, glassblowing and weaving demonstrations will also be held at the complex.

Also on Saturdays and Sundays, a horse-drawn carriage will, for a small fee, carry shoppers between Market Station and the Loudoun Museum. This Saturday only, the Museum (on Loudoun Street) will conduct home tours from 1 to 8, giving shoppers an opportunity to explore the diverse mix of architectural styles in Leesburg against a background of greenery, fruit, candles and holly.

Other Leesburg Christmas celebrations include Oatlands, a property of the National Trust for Historic Preservation, open for tours 10 to 4:30 Monday-Saturday through December 23 (with candlelight tours 6 to 9 p.m. Saturdays and Sunday tours from 1 to 4:30). Admission is $5 for adults (candlelight tours are $6), $4 for senior citizens and children 12 to 18 (under 12 free). The historic mansion at Morven Park will be open for Christmas tours Friday through Sunday 1 to 5 p.m. Admission is $5.