The crossword solution for the term 'BIG EVENT SITES' is 'STADIA, ' which is a six-letter word. STADIA are large venues that are used to host major events such as concerts, sports games, and other large gatherings. They are typically designed to accommodate large numbers of people and often feature seating areas, concession stands, and other amenities. STADIA are often associated with professional sports teams, but they can also be used for other types of events.