Which one of these is NOT one of the 5 influential stadiums?

The Stadium of Delphi is not considered one of the five influential stadiums in the context typically referenced in discussions about historic and impactful sports venues. While the Stadium of Delphi holds significant cultural and historical value, particularly as the site of the ancient Olympic Games and other athletic competitions in ancient Greece, the five influential stadiums usually highlight those that have had a profound impact on modern sports culture and architecture.

Old Trafford and Camp Nou are well-known for their roles in contemporary football (soccer) history and have been central to the identities of their respective clubs, Manchester United and FC Barcelona. Similarly, the Colosseum, although primarily an ancient amphitheater, represents the historical foundation of stadium design and is often included in discussions for its legendary status in sports and entertainment history. Thus, the focus on influential stadiums is more aligned with modern implications and large-scale cultural significance, making the Stadium of Delphi an outlier in this particular context.