Dunsink Observatory. Castleknock, Dublin 15 is located about 8 kms northwest of Dublin city centre, in the suburb of Castleknock. Easily accessible by car, head for Castleknock along the N3 out of Dublin and turn right at the intersection with Auburn avenue just before reaching the M50 onto Dunsink Lane. Then proceed past the Travelodge motel, the junction with the New River Road and Elmgreen golf course to reach the Observatory. Coming from the M50 take the exits marked N3 City and then follow signs for New River Road onto Dunsink Lane. If coming from Auburn Avenue and the Phoenix Park just go straight across the N3.
Buses (numbers 38 and 39) towards Blanchardtown leave from the city centre. Get off at the bus stop after the Auburn Avenue/New Dunsink Lane intersection on the Navan Road, cross over to New Dunsink Lane and follow it for the next two miles. Taxis are strongly advised after dark.