F.B. Meekins Pre-school marches in the Vienna Halloween Parade every year. On Wednesday, Oct. 24 starting at 7 p.m., around 35,000 participants and spectators will descend upon Maple Avenue under the auspices of the 66th Annual Vienna Halloween Parade, led by a swarm of costumed children. The parade proceeds to Center Street, marching under this year's theme, "Celebrating Holidays Around the World," with Grand Marshal Santa Claus leading; the entirely volunteer-run parade can use your help, too. www.viennahalloweenparade.org.