Go Walk: the Grand Canal Way, Co Offaly

I left Tullamore on a proper Irish spring morning: icy wind on my face, warm sun on my back. My plan was to follow the Grand Canal Way west through the boggy heart of the midlands.

Just outside Tullamore the canal passes Shra Castle, built in 1588 by an English solider who married into a local family. But Ballycowan Castle, a bit further on, is even more striking.

Nearby the towpath crosses two aqueducts, engineering marvels that lift one waterway above another. Further on I spotted a peacock butterfly, my first of the year, its rusted wings spotted black, cream and lilac. The countryside here was flat and farmed. Some fields were wonderfully disordered, with overgrown hedgerows and rough grass. Others were smooth and symmetrical, their hedges hacked bare.

Seeing this, I thought of an eccentric landowner in the midlands who once who told me that when walking his land, I would know where his farm ended because the fields would suddenly become boring. He celebrated disorder, and I imagined him cursing the neatest fields beside the canal.

Later I was resting by a bog oak sculpture at Pollagh when a barge named the Cheerful Lady passed. She had left Tullamore when I did, but had fallen behind me waiting at a lock. "Maybe if you get tired they'll give you a lift," the man from Waterways Ireland had said. The barge and I exchanged pole position a few times until she pulled ahead at Pollagh, and that was the last time I saw her.

Past Pollagh the towpath vegetation was stripped bare, and I had to trudge through peaty mud. The Grand Canal Way stretches from west Dublin to the Shannon, and is marked along its whole length. The walking is flat, but in places the towpath is rough and muddy, so wear good walking shoes. Though this section follows quiet roads in parts, I encountered few cars. Make sure you stick with the waymarkers – if you walk on the opposite bank, you could find yourself hitting a dead end.

Then the land grew wilder, and the blooming gorse gave away its secret: I had entered bog country, where the canal passes through Bord na Móna’s great cutaway peatlands. The houses disappeared, and the land between towpath and bog filled with a hodgepodge of scrub, wood and field, more interesting that any single habitat. Nearby are the Turraun Wetlands, created when Bord na Móna flooded its exhausted peat fields. They form one section of Lough Boora Parklands, 2,000 hectares of cutaway bog where nature has retaken hold to create lakes, meadows, scrub and woodland. The parklands have walking trails, hides for birdwatching, bike hire and angling lakes.

Along the canal the towpath crosses one of Bord na Móna’s bog railways. Nearby something big seemed to tumble into the canal from the reeds. I scanned the water for an otter’s head, but none appeared. Later I watched a heron stalk fish from the towpath.

Early in the evening, I left the canal at Gallen and walked 2km by road into Ferbane. I had just enough time for a tipple before catching a bus out of the bog country.