The R821 road is a regional road

Regional road

A regional road in Ireland is a class of road not forming a major route , but nevertheless forming a link in the national route network. There are over 11,600 kilometres of regional roads. Regional roads are numbered with three digit route numbers, prefixed by "R" A regional road in Ireland is a...

 in south Dublin, Ireland

Republic of Ireland

Ireland , described as the Republic of Ireland , is a sovereign state in Europe occupying approximately five-sixths of the island of the same name. Its capital is Dublin. Ireland, which had a population of 4.58 million in 2011, is a constitutional republic governed as a parliamentary democracy,...

. The road starts at the junction with the R115

R115 road

The R115 road is a regional road in counties Dublin and Wicklow in Ireland. It follows the Military Road for its entire length. The R115 is long; the full length of the Military Road is...

 (Willbrook Road) in Rathfarnham

Rathfarnham

Rathfarnham or Rathfarnam is a Southside suburb of Dublin, Ireland. It is south of Terenure, east of Templeogue, and is in the postal districts of Dublin 14 and 16. It is within the administrative areas of both Dun Laoghaire-Rathdown and South Dublin County Councils.The area of Rathfarnham...

 and passes through Nutgrove

Nutgrove

Nutgrove is an area in Rathfarnham, County Dublin.It is a suburban area at the foot of the Dublin mountains between Churchtown and Rathfarnham around the Nutgrove Shopping Centre....

 before terminating at Churchtown

Churchtown, Dublin

Churchtown is a largely residential suburb on the southside of Dublin, Ireland, between Dundrum and Rathfarnham. It is in the postal districts Dublin 14 and Dublin 16.- Ely's Arch :...

.

Route

• The road starts at the T-junction with the R115
  R115 road
  The R115 road is a regional road in counties Dublin and Wicklow in Ireland. It follows the Military Road for its entire length. The R115 is long; the full length of the Military Road is...
  
   (Willbrook Road) beside the well known The Yellow House pub. The road heads in an easterly direction and is known as Grange Road.
• About 350 meters further the Grange Road turns off in a southerly direction as the R822
  R822 road
  The R822 road is a regional road in south Dublin, Ireland. The road starts at the junction with the R821 in Rathfarnham before terminating with the junction with Taylor's Lane on the R113. The road is known as Grange Road throughout....
  
   while the R821 continues easterly as Nutgrove Avenue.
• The route passes the shopping center and retail park in Nutgrove after a crossroad with local roads.
• The route terminates at a triangle in Churchtown
  Churchtown, Dublin
  Churchtown is a largely residential suburb on the southside of Dublin, Ireland, between Dundrum and Rathfarnham. It is in the postal districts Dublin 14 and Dublin 16.- Ely's Arch :...
  
   where it connects with the R112
  R112 road
  The R112 road is a regional road in south Dublin, Ireland. It begins at the junction with the N4 road at Chapelizod and arcs southeastwards, then eastwards across the middle of south Dublin, ending at the Mount Merrion junction of the N11. The road is single carriageway, with cycle lanes on some...
  
   (Upper Churchtown Road) and a local road (Beaumont Avenue).

Transport

A westbound bus lane is present along the entire route while after Nutgrove there is also a bus lane heading east until the end of the route in Churchtown. There are a number of Dublin Bus

Dublin Bus

Dublin Bus is a public transport operator in Ireland. It operates an extensive bus network of 172 radial, cross-city and peripheral routes and 18 night routes in the city of Dublin and the Greater Dublin Area. The company, established in 1987, is a subsidiary of Córas Iompair Éireann which is...

 routes along the R821:

• 16
• 16A
• 17
• 75

There is an off steet bike lane on the route though there are a few sections where the lane ends unexpectedly.

Future plans

Currently there are plans to upgrade the junction with the R112

R112 road

The R112 road is a regional road in south Dublin, Ireland. It begins at the junction with the N4 road at Chapelizod and arcs southeastwards, then eastwards across the middle of south Dublin, ending at the Mount Merrion junction of the N11. The road is single carriageway, with cycle lanes on some...

and Beaumont Avenue.