The North Circular Road is an important thoroughfare on the northside of Dublin, in Ireland. The regional road was long considered the northern boundary of the city and still separates the city centre from the inner suburbs. It runs from the Phoenix Park in the west through Phibsboro, to North Wall in the east. A number of important institutions are located along the road, including the Mater Hospital, Dalymount Park and Mountjoy Prison, and both Croke Park and St. Brendan's Hospital are nearby.
The R101 and the NCR overlap for most of their lengths, and the entire NCR forms a section of the R101. In the west the R101 connects the NCR to Parkgate Street via the short Infirmary Road ; at the eastern end the R101 becomes Portland Row after the junction with Summerhill. It continues the northern loop through Saville Place , then turning east for its final kilometre via Sheriff Street (Upper) before terminating at North Wall Road (the R131).