Newgrange is one of Ireland's most incredible sites - but despite it and the surrounding Brú na Bóinne complex being an area of intense historical interest, and having been studied now for hundreds of years, it is still revealing more and more discoveries.Just last week, a team of archaeologists lead by UCD's Dr Steve Davis uncovered around 40 previous unknown sites of interest.In this week's episode of The Explainer, presenter Sineád O'Carroll is joined in studio by editor of Archaeology Ireland Dr Sharon Greene, Dr Jessica Smyth of UCD's School of Archaeology, and TheJournal.ie's editor Susan Daly to examine why, including the new techniques that have led to recent discoveries and the roadblocks that archaeologists face when they want to examine a site in-depth.