Hiding between the wild coastlands of Mayo and Donegal, Sligo’s landscape is less dramatic but more lush and green. Benbulbin draws most of the county’s plaudits, so other hills are forgotten. The 78km Sligo Way traverses the county’s less trodden, boggy uplands. I wanted to spend a day exploring it, so headed for the village of Collooney.

From here the trail follows the Owenmore and Ballysadare rivers into Union Wood, where old oaks and mossy crags sit uncomfortably beside spruce plantations. Further east it crosses the high heathlands of Slieve Daeane.

I had feared a dull slog over this hill but instead found real drama at Lough Lumann, a mountain lake with a backdrop of tall heather-coated crags. Showers passed over and mist erased the summit. This is the best kind of hill weather, an interplay of sun, cloud and rain that changes the light and landscape with each moment.

It’s impossible to write about Sligo without reference to Yeats, whose words have become a filter through which we see the county. He wrote “we should make poems on the familiar landscapes we love, not the strange and rare and glittering scenes we wonder at”.

According to John Cowell's book Sligo: Land of Yeats' Desire, a chamber tomb near the summit of Slieve Daeane is known as Cailleach Beare's house. In a note to his poem The Hosting of the Sidhe, Yeats explains that Cailleach was a fairy who "went all over the world seeking a lake deep enough to drown her faery life . . . until, at last, she found the deepest water in the world in little Lough Ia" on top of this hill. But this lake's name wasn't on my OS map.

After coming off Slieve Daeane, the trail enters Slish Wood and follows a stream toward the shore of Lough Gill. Yeats was inspired by Walden, Henry David Thoreau's classic account of life in the Massachusetts woods, to spend a night sleeping here. "I planned to live some day in a cottage on a little island called Innisfree, and Innisfree was opposite Slish Wood where I meant to sleep," he wrote. He spent a night under the trees, but barely slept for fear of being discovered by the wood-ranger. "However, I could watch my island in the early dawn and notice the order of the cries of the birds."

If anybody lived here like Thoreau, it was Beezie Gallagher, who was born on the lake’s Cottage Island and later returned to live there, rowing into Sligo regularly. She hand-fed birds and squirrels inside her cottage, and banned a visitor who threw stones at rats. She was rescued after a blizzard in 1947, then in her 80s, but rowed back to her island home after a week of recuperation. She died there in a fire in 1951.

Leaving the forest, the trail crosses rough bogland and woods before emerging to a slipway that looks out on Inishfree, the end point of my walk through Yeats country.