A walk along the Carrigaline to Crosshaven Greenway. Carrigaline is very easily reached from Cork City by the frequent Bus Eireann 220 bus. I got off at the Kilmoney stop, and started the track nearby at the roundabout near Lidl, where there is a signpost for the Greenway.
The Greenway initially goes along the roadside, but soon diverges and follows the Owenabue river to Crosshaven. It runs quite close to the main road throughout, through, and the sound of traffic is a constant accompaniment.

My tip is once you reach Crosshaven to do some of the walks on the roads and tracks north and east of the village. There’s a great viewpoint over the sea from the road at the top of the hill to the east, and various tracks along the seashore around the north east. I happened to see an information board about the walks in the Centra in the village, and kind of followed it but mostly rambled around. (I didn’t get this part of the walk on GPS.) This was probably better than the actual Greenway, albeit the tracks are informal and sometimes muddy, and not well signposted.
The photos below are from the Crosshaven walks, not the Greenway: