Which of the following is a significant cultural heritage site located in Northern Ireland?

The Giant's Causeway is a significant cultural heritage site located in Northern Ireland and is renowned for its unique geological formations, consisting of around 40,000 interlocking basalt columns formed by volcanic activity. It is not only a natural wonder but also steeped in folklore and myth, associated with the legend of the giant Finn McCool. The site holds great cultural significance and is recognized as a UNESCO World Heritage Site, highlighting its importance in terms of both natural and cultural heritage.

The other sites listed, while historically and culturally significant, are located in different parts of the UK and do not represent Northern Ireland. Stonehenge is in England, known for its prehistoric monument; the Tower of London also lies in England, famous for its history and as a royal palace; and Hadrian's Wall, which is located in northern England, was built by the Romans and marks the northern limit of the Roman Empire in Britain.