The remains of "monumental temples" dating to the Iron Age and medieval buildings may be hidden underground at Navan Fort, an archaeological site in Northern Ireland, a new study finds. Exactly what's left of these ruins, however, remains to be seen. Archaeologists discovered the buried structures by using remote-sensing techniques that allowed them to map the hidden landscape and detect anomalies, such as architectural features made by humans. These Iron Age and medieval buildings suggest that Navan Fort was "an incredibly important religious center and a place of paramount sacral and cultural authority in later prehistory," study co-researcher Patrick Gleeson,...