Día de los Muertos is a celebration honoring the deceased that takes place in Mexico and other parts of Latin America on Nov. 1 and 2. The holiday is celebrated through ritual observations like constructing altars, ofrendas, filled with offerings to the dead and decorating family gravesites to commune with the dead. It is also commemorated through fiestas in which communities gather to celebrate by dancing, playing music, feasting, drinking and masquerading as death.
Community celebration activities can be found here and here.