Inishowen Peninsula Military Road — Mamore Gap to Gap of Mamore Fort via Urris Hills

The Gap of Mamore sits at around 820 feet above Lough Swilly on the Inishowen Peninsula in County Donegal — and getting there from the Urris side is a white-knuckle single-track haul with grass growing down the middle and sheer drops that’ll make your passenger grip the door handle. The route runs from the coastal village of Dunaff up through the Urris Hills, cresting the gap and descending toward Lehanmore and the R238 near Clonmany. An old military watchtower ruin sits near the summit, a remnant of the Emergency-era coastal lookout network that monitored Atlantic approaches during WWII. Below you the entire length of Lough Swilly opens up — one of Ireland’s great sea loughs — with the Fanad Peninsula beyond. It’s a short route but it hits hard.

Don’t let the mileage fool you — the gradient on the Urris approach exceeds 20% in places and the surface is rough broken tarmac transitioning to loose stone near the crest. A standard SUV can make it in dry conditions but you’ll be uncomfortable; a proper 4WD with decent ground clearance runs this with confidence. In wet weather the road surface becomes greasy stone and the descent toward Clonmany demands careful braking. No permits required — this is a public road. Nearest fuel in Clonmany. No cell service at the summit. Best avoided in ice; October to March can be treacherous. The views from the top on a clear day are worth every anxious moment of the climb.