I went to Dublin seeking wild landscapes, not really expecting to find any. Living on the west coast I usually don’t travel far for this sort of thing. Going to Dublin to find mountains felt incongruous.

Zig-zagging over the hills from Tallaght to Shankill, the Dublin Mountains Way is two years old. I started from the trailhead at Seán Walsh Park, Tallaght, aiming to make Glencullen by sunset. The trail skirted housing estates, then dropped me into comparative wilderness around the Bohernabreena reservoir, where the river Dodder was damned in the 1880s and wooded hills fall to the lakeshore.

This valley is also home to orchid-rich grassland and petrifying springs, where lime-rich water rises from the ground and deposits calcium carbonate in a white, crunchy coating.

The trail brought me into the hills, looking over to lime and rust-coloured slopes on Seahan and Corrig mountains. Walkers need to be cautious as this section is on narrow, windy roads.

I expected Celtic Tiger mansions up here and there were some. But it was mostly old stone cottages, hay sheds, farm yards and signs warning that dogs worrying sheep would be shot.

This valley – Gleann na Smól, glen of the thrushes – was one of the last places in which the Irish language survived near Dublin.

Heavy mist pressed down on the hills as I climbed. And though I couldn’t see them, I was surrounded by mountains.

The trail entered the Featherbed forest, but the name felt euphemistic as it crossed felled planation. I felt like a lone survivor in the aftermath of some brutal apocalypse, surveying a landscape of decaying tree stumps, black pools, churned peat and a few limbless trees. It reminded me of the writer Tim Robinson’s description of clear-felled forest in Connemara as “frozen at a moment of maximum horror”.

But soon I entered the forest at Cruagh, passing a mossy stone bearing an inscription to the naturalist HC Hart, who in 1886 bet a colleague that he could walk the 111km from Terenure to the summit of Lugnaquilla in Wicklow and back within 24 hours.

He won, returning to Terenure with 10 minutes to spare. The trail followed rows of mature spruce trees, heather, mosses, and flowering gorse.

I went up Tibradden Mountain and towards the summit of Two Rock, the way’s highest point. Writer and nationalist Stephen Gwynn described this area as “bare and lonely, as devoid of any suggestion of a great city’s nearness as even Connemara could show”. This is what I had come looking for, but I could only see a few metres of the trail rising into the clouds ahead of me.

Soon a gust of wind blew off the clouds to reveal Fairy Castle, Two Rock’s summit tomb, and the orange glow of the city below.

The trail brought me towards the huge transmitters at Three Rock. Writing in 1780, the artist Gabriel Beranger reckoned the mountain’s distinctive rock clusters were altars built to offer sacrifices. They are, in fact, natural granite formations.

But I was in trouble: the walk had taken longer than planned and the sky was blackening, so I donned a headlamp and high-vis jacket to descend Ticknock forest in the dark. The final stretch into Glencullen on country roads in the dark was the most treacherous bit of my walk – without a headlamp I’d have been in serious trouble.

The lesson? Walking from Tallaght to Glencullen is probably too much at this time of year – if you want to walk this route in winter, tackle it over multiple days, or just pick a sub-section.