Altnadua Lough

Walking boots squelch through boggy ground as you approach this dark mountain tarn, tucked away in the Mourne Mountains between Newcastle and Castlewellan. The lough sits in a natural hollow, surrounded by heather and rough grassland that turns purple in late summer.

Serious walkers and photographers will get the most from Altnadua Lough. It's not particularly large or spectacular - more a contemplative spot than a showstopper. The water reflects the surrounding peaks on still days, creating decent photo opportunities for those who've made the effort to reach it.

Getting there requires proper walking gear and reasonable fitness. There's no marked path to the lough itself, so you'll need basic navigation skills and waterproof boots. Allow three to four hours for the round trip from the nearest car park. Weather changes quickly up here, so pack layers.

Families with young children should probably give this one a miss - the terrain is challenging and there's nothing to hold kids' attention once you arrive. Keen hikers staying at nearby Tollymore Campsite or the glamping options around Castlewellan will find it makes a good half-day expedition, especially combined with other Mourne peaks. The Rock Caravan and Camping sits closest to the mountain access points, making it a sensible base for serious hill walkers.