In order to encourage residents to stay in town when these cities are at their hottest and to bring people into the sweltering heat, many hold summer festivals including concerts, cultural events, and fireworks!
Lucca (20 km from Camp Darby): http://www.summer-festival.com/
Valencia: http://www.feriadejulio.com/ While complete details aren’t published yet, there is always, and I mean always something fun to do in Valencia in July. Concerts, flamenco dancing, an absolutely amazing International Fireworks display at the end of the month, bullfights, and the unique “Battle of the flowers” during which both the participants and the onlookers in this beautiful floral parade engage each other in a crazy flower throwing fight that lasts about 20 minutes and ends with a noisy display of ground fireworks.
Good Links: (so as not to reinvent the wheel)
A really good list at about.com: http://goeurope.about.com/od/festivalsineurope/a/summer_fests.htm
Can’t go wrong with Rick Steves: http://www.ricksteves.com/plan/destinations/europe/fest_menu.htm