The Mound of the Hostages, or Duma na nGiall, is a significant archaeological site on the Hill of Tara, Ireland, serving as a Neolithic passage tomb dating back over 5,000 years.

It's the oldest visible monument on the hill and was used for burials for over 1,500 years after its construction. The mound's name comes from medieval lore, suggesting it was a place of symbolic hostage exchanges. 

Photo by Sanjoy Som