When fifth-century B.C. Celtic villagers first donned scary garments for All Hallows Eve, they did it for a practical reason -- to prevent lost souls from invading and taking over their bodies. Today, we just want a spooky good time and bags of quality candy. To help your quest, we asked the members of the Inside Source (www.washingtonpost.com/insidesource), the Sunday Source's reader community, to clue us in to the area's best trick-or-treating spots. We also combed the archives, talked to neighborhood associations and interrogated current residents about their Halloween-crazed hoods. Our best bets:

Bubble, Toil and Trouble in Mount Pleasant. Head for the boiling cauldron on Lamont Street -- it's the center of the festivities in this Northwest neighborhood. You won't find Macbeth's witches, but after 4 p.m., the stretch between 17th and 19th streets is closed to traffic and turned over to a roaring, s'mores-friendly fire, pumpkin-carving parties, outdoor grilling and lots of hot-apple-cider-sipping folk resting on bales of hay (the street opens again at 9 p.m.). Get ready for competition, though: Longtime resident Laurie Collins started the tradition 10 years ago, and now Halloween night attracts more than 300 kids.

Embassy Row's International Treats. Head out early if you want to hit this Massachusetts Avenue stretch, which has been popular with college students and adventurous yuppies for decades. Calling ahead will also save some heartbreak: Not all embassies play along. Head north from Dupont Circle until you hit the Turkish Embassy, just past California Street, then turn right toward the ambassadors' residences on Belmont Road or Edgevale Terrace (off 30th Street), keeping your eyes peeled for culture-meld decor like the occasional Romanian Dracula. An added highlight? Wowing Halloween novices among the embassy staff.

M&Ms and Martinis in Old Town. Alexandria's unofficial Halloween bash understands that adults love the holiday, too: While little monsters find full-size chocolate bars behind decadently decorated doors on Lee Street between King Street and the park, adults may score a cold margarita or shaken martini. Old Town resident and Insider Mari Stull said her in-laws travel from Delaware for the festivities: "It has to be seen to be believed."

A Homey Halloween in Country Club Hills. This neighborhood's fest, held in the 35th Road North cul-de-sac, is an intimate affair. Neighbors block off traffic and set up haunted houses, pumpkin tosses and cookouts. Residents trick-or-treat down one side of the street, stop at the block party and continue their quest for goodies down the other. The best part? The plentiful candy. "This year, my son said, 'I better take a garbage bag,' " said resident and Insider Paige McKenzie.

Spooky Scenes in Kensington. Smoke machines, flying ghosts and scary music distinguish the aptly nicknamed "Scary Perry" Avenue, between Lexington and St. Paul, where, according to resident Jodi Westrum, it's so "mandatory" to decorate that even if someone can't do it, "the neighbors do it for them." Families from all over enjoy the final product, said Insider Rebecca Penovich, who drives over from Capitol View Park to soak up the theatrics. "We took our son for his first Halloween last year," she said.

Lauren Silva

To kids young and old, may your plastic jack-o'-lantern runneth over.