Slane Bridge sates from the 14th Century, but major improvements were carried out on the structure in 1776.
There are 12 arches.
Leaving Newgrange, we drove along the Boyne Valley, paralleling the River Boyne and traveling down river. We drove through the Village of Slane and past many interesting ruins.
The second stop was the Hill of Tara, the seat of well over 100 kings in historic and prehistoric times. The hill has hundreds of ruins, markers and other structures including another megalithic tomb called the Mound of the Hostages. The hill is more broad than tall (500 feet tall and 1,000 feet by 800 feet), but we could see part of about half the counties of Ireland at the summit near the 1822 deconsecrated Saint Patrick's Church which now serves as the visitor's center.
The Stone of Destiny at the top of this page is supposed to let out a screech that can be heard all over Ireland if the next King of Ireland touches it. I didn't touch it and take the chance.
During the bus ride back to Dublin, Mary Gibbons, encouraged people to visit the National Museum of Ireland to see artifacts relating to the locations which we had visited during the tour. One of the drop off points was near that museum, but we chose to be dropped at the same place where we were picked up in the morning.
Returning to Dublin in the late afternoon, we explored some of the shops along and near O'Connell Street, Dublin's main thoroughfare. The rain was still coming and going, but heavier and after visiting a few shops we took a taxi back to our hotel for a brief break before the evening.