Nola, a town east of Naples just off the A16 autostrada, has a long history (Roman emperor Ceasar Augustus died here) and an odd but fascinating festival of the Gigli (Lillies) each June.
The feast actually lasts for most of June (indeed, preparations begin months in advance), but the main event is on the first Sunday after (or on) June 22nd. On that day, starting around 9 AM, each of the nine gigli (8 spires plus the 1 boat) start a long procession/march/dance/concert from various quarters of the city to the Piazza del Duomo in the center of the city. They all meet there around noon, where the bishop blesses the crowd and the gigli, and San Paolino's relics are paraded around. There is a brief pause in activity (for riposo, of course!) from about 2 until 4, when a city-wide parade begins, whose festivities end quite late.Official schedule (in Italian): www.meridies-nola.org/festagigli/festagigli.html
Very detailed description of events, including a description of the parade route (in Italian): www.giglidinola.tv/site/festa_attuale.html (site is down but check out this archive)
From Naples, take A1 north to A16 heading towards Bari. Follow signs for Nola; once you get close, follow signs for the Centro. Parking lots at Piazza d'Armi at 40°55.7'N 14°31.8'E. Piazza del Duomo is at 40°55.56'N 14°31.65'E, but you can't drive anywhere near there. There is also a train, but it runs infrequently.
Dvinus - Piazza Giordano Bruno 13, 081-362-6500, closed Sun eve, Mon, rec'd by Gambero Rosso and Espresso
Le Baccanti - Via Puccini 5, 081-512-2117, closed Sun eve, Mon, rec'd by Gambero Rosso, Espresso, and Michelin
Gelateria Zaza, Melodia del Gelato - "Vulcano Buono" rec'd TCI
A number of Nola residents emigrated to Williamsburg, Brooklyn, where each year Our Lady of Mt. Carmel sponsors a gigli festival. Walkinginbrooklyn has a great description of the festival, along with videos. The most famous US gigli festivals are detailed at gilio-usa.org. The Sons of San Paolino also put on an event in Glen Cove, NY. The New York Folklore Society published a nice article called "Born to Giglio" about these US festivals.