Pictures taken from Hill of Tara and Newgrange. Newgrange is one of the oldest passage tombs, a monolithic monument built 3000-5000 BC, that predates Stonehenge. There's a few tombs like this scattered in Ireland. I think Knowth nearby is bigger, but they don't allow the public in. There are many smaller mounds nearby, one clearly visible from Newgrange.
View of the landscape from the Hill of Tara
Waterscape near the entrance to the Newgrange tomb area.
Newgrange Tomb
Entrance to Newgrange Tomb. The beautiful stone markings are still somewhat of a mystery.
On the winter solstice, the sunlight shines through the entrance of the tomb into the inner chamber.
Unexplored mound near Newgrange