Discover the secrets of the Silent Valley Reservoir

Ringed by the Mourne Mountains, the Silent Valley Reservoir and nearby Ben Crom Reservoir are among the stand-out experiences of the Mourne Area of Outstanding Natural Beauty and UNESCO Global Geopark. This landscape is dramatic and atmospheric, with jagged mountains rising out of the sea, and rock formations creating images of hags and giants.

No wonder CS Lewis, a Belfast man, frequented this area, often getting inspiration for Narnia in places such as the Pot of Legawherry, Buzzard’s Roost, Devil’s Coach Road or Lamagan Slabs. The names, and the terrain, will have impressed and inspired the great storyteller. The atmosphere too: when the wind blows in these parts you’ll swear you can hear some distant ethereal howling. The whole place seems to have tumbled out of a fairytale.

A curious stone construction encloses the reservoirs of Silent Valley and Ben Crom – a dry-stone granite wall that extends some 35km across 15 summits. This is the Mourne Wall, which stands 1.5 metres in height and reaches to the top of the highest peak in Northern Ireland, Slieve Donard. In days gone by this mountain view supported an entire postcard industry; today it’s an Instagram favourite,

You can find out about the wall – or “the black ditch of Mourne” as it was called by those who constructed it back in the early 1900s – at the Silent Valley Mountain Park Visitor Centre. It was put there by the water supply company, quite simply, to keep livestock away from the water. Today, with sophisticated purification measures, that original purpose has expired; but the wall, crafted from granite using traditional dry-stone walling techniques, remains.

The Silent Valley Visitor Centre stands at the southerly end of the reservoir. But you’ll need to tear your eyes away from the awesome view for a few minutes to see an exhibition that gives you the lowdown on this place.

Within the centre the historical details of the whole Silent Valley project are laid out in imaginative fashion. There’s a replica of a section of the Binian Tunnel, a key part of the whole enterprise, built from 1949 to 1958 to carry water from the Annalong River to the Silent Valley

The settlement of Watertown sprung up to accommodate the many engineers and labourers involved in the original building work. The “town” at its peak, was home to around 600-700 engineers and labourers who built the reservoirs and the Mourne Wall.  Fact fans will be interested to learn that the town had its own cinema, hospital and police station – and may have been the very first place in Ireland to have been lit by street lamps.

At one time it would have been muddy and cheerless. Today the walk down from the reservoir is lined with rowan, ash, and oak, and in the spring the meadows are alive with bluebells and celandine. One of the former houses has been refurbished and opened to give a comprehensive idea of what life was like for these workers in the early 20th century.

The visitor centre will also give you an overview of the wildlife that calls this place home. Red kites and kestrels miss nothing as they gaze around the terrain hoping to spot a likely snack; ravens tumble through the sky showing off their aeronautic skills; and if you’re lucky, you might spot the world’s fastest animal. The peregrine falcon, which nests on cliffs throughout the area, catches its lunch by dive-bombing on top of it from several hundred feet up in the sky. If a peregrine is only doing 120km then it’s dawdling along. More pastorally, in spring the larks sing their chorus high in the sky above the heather, and wheatears skip from rock to rock.

Within the Silent Valley Mountain Park several trails crisscross the mountains, woodland and parkland. The Ben Crom Dam Walk, some 10km, takes you to the Ben Crom Reservoir, passing the exit of the Binian Tunnel. The Brandy Pad skirts both reservoirs. This old smugglers' trail starts at the Bloody Bridge – the scene of an ancient battle, as you’ve probably guessed – overlooking the Irish Sea. The trail heads up through Poulaphouca, the Glen of the Fairies, onwards to the Hare's Gap and the slopes of Slievenaglogh. Along this path shepherds have trudged, rebels and outlaws on the lam have scarpered, and smugglers have plied their trade.

North of Ben Crom, just off the Brandy Pad, are the Diamond Rocks. Look out here for “Mourne diamonds”: beautiful pieces of smoky quartz and black mica crystals set deep in the granite. Any small crevice in the rock may yield this treasure. Impressive, glittering, but alas worthless in monetary value. The time spent in the Silent Valley, however… that’s priceless.