Brittas sits at the foot of the Dublin Mountains in the south-west of the county, about 25 km from the city centre and a kilometre or two from the Wicklow border. There is no tourist infrastructure, no heritage attraction in the village itself, and no particular reason to come unless you are heading for the Glenasmole Valley - which is a very good reason.
The Glenasmole Valley runs north from the foothills, carrying the River Dodder through a deep glacial trough past the Bohernabreena Reservoirs. The reservoirs were built in the 1880s and still supply south Dublin. The valley access roads give you walking on flat ground with mountain views - quiet, managed, and almost entirely unvisited by the Dublin tourist circuit. The Brittas Ponds, artificial lakes north of the village, were created to serve old paper mills in Saggart. They're good for a walk.
Three things every local will eventually mention. Read these and you've already understood more than most day-trippers do.
Bohernabreena Reservoir sits in the Glenasmole Valley ten minutes north of Brittas - two reservoirs built between 1883 and 1887, supplying 18 million litres to south Dublin daily. The valley is managed access, with good walking on the reservoir roads and the Dodder valley above.
Walks & outings → 02 The nameBrittas Bay is in Co. Wicklow, about 50 km south. It gets all the fame. This Brittas - closer to Saggart and Rathcoole, in the Dublin Mountains foothills - is a quiet rural settlement that routinely gets traffic meant for a beach it has never seen.
Stories & lore →The reason to come back. The things every local will eventually tell you about, usually after the second pint.
Wear waterproofs. Bring a sandwich. Tell someone where you're going if it's the mountain.
There is no bad time. There are different times.
The Glenasmole Valley is particularly good in spring - the Dodder running high, gorse on the lower slopes, and the reservoir roads quiet.
The foothills stay cooler than the city in July heat. If Brittas Bay is packed, Glenasmole is a completely workable alternative day out.
The best colour in the upper valley is in October. The reservoir loop is at its best when the bracken turns.
The upper valley tracks can be wet. The reservoir road stays walkable most of the year. Dress for wind from the mountain above.
If a local was sitting beside you, this is the bit where they'd lean in.
That beach is in Wicklow, 50 km south. If that's what you want, keep driving on the N11.
Brittas is a rural settlement, not a village with a main street. There is no pub, no café, no shop in the village itself. Saggart (3 km east) or Rathcoole (5 km north-east) have the basics.
From Dublin city, take the N81 south toward Blessington and turn right at Jobstown/Saggart. Brittas is about 25 km from the city centre, 30 minutes without traffic. For Glenasmole, follow signs from the Bohernabreena Road off the R114.
Dublin Bus 65 runs from the city to Saggart, 3 km from Brittas. From there it is a walk or a taxi. Glenasmole valley is not served by public transport.