From National Geographic: Ancient "Royal Temple" Discovered in Path of Ireland Highway.

The discovery of a major prehistoric site where experts believe an open-air royal temple once stood has stalled construction of a controversial four-lane highway in Ireland.

A large circular enclosure estimated to be at least 2,000 years old was exposed at Lismullin in County Meath, by road-builders working on a 37-mile-long (60-kilometer-long) road northwest of Dublin (see map of Ireland).

The find is located just 1.25 miles (2 kilometers) from the Hill of Tara, once the seat of power of Ireland’s Celtic kings, and likely represents a ritual site, according to government archaeologists attached to the road project. [continue]

Thanks to Sarah for telling me about this story.