Overview
Lough Allen is the first of the River Shannon’s three big lakes, and the one most people drive past. The young river runs into its broad northern end and straight out of the narrow southern tip, near the top of its course. About 17.7 km long and 4.8 km at its widest, it lies mostly in County Leitrim with a fringe in County Roscommon, ringed by the iron hills that gave the area its old industry. The clear, low-nutrient water drops to 31 m at its deepest. The R280 runs down the western shore and the R207 the eastern, a short drive from Drumshanbo, Dowra and Drumkeeran.
Water Sports & Lakeside Wellness
The Lough Allen Adventure Centre, on the shore near Drumshanbo, is the hub for anything on the water. Guided kayaking and stand-up paddleboard tours run out onto the Drumshamazon, a sheltered channel winding between islands and a working lock, usually at 11am and 3.30pm; buoyancy aids and wetsuits are provided, and children from age four can join. Adventure Gently runs guided Canadian-canoe trips on the lake as well.
Out of the water, the centre’s wellness side is what draws a lot of visitors: a wood-fired sauna, a cold-plunge pool and an open-air jacuzzi looking out over the lake to the Arigna Mountains, plus yoga in a lakeside yurt and seasonal Wim Hof workshops. The on-site Wild Way Café does locally sourced food, and an Epic Water Park and Climbing Wall is due to open here in spring 2026. None of it is free – the shoreline is, but the activities and the sauna are booked and paid through the centre’s website.
Hiking & Cycling
The landscape around Lough Allen is threaded with trails that mix long views and industrial heritage. Sliabh an Iarainn, the Iron Mountain, rises steeply along the eastern shore and gives panoramic routes back down over the lake and its valleys. For something longer, the waymarked Miner’s Way & Historical Trail follows the eastern shore between Dowra and Drumshanbo, threading past old mining sites, stone bridges and quiet woodland.
Cyclists can follow the Shannon Blueway, a well-signed route that runs alongside the lake and connects to the wider Shannon waterway network. The floating boardwalk over Acres Lake near Drumshanbo provides a short, accessible loop perfect for families or a gentle evening stroll.
History & Archaeology
The shores of Lough Allen have been inhabited since the Mesolithic period. Archaeologists have recovered nearly a thousand stone tools from the shoreline, including some of the earliest lake-side axe roughouts found in Ireland. Inishmagrath, one of the lake’s islands, is traditionally a monastic site, and Tarmon on the shore is linked in local tradition to St Patrick. Several crannogs – artificial timber and stone islands used as dwellings in prehistoric and medieval times – still dot the lake.
The lake’s industrial past is just as present. Iron ore from the Slieve Anierin hills was shipped across Lough Allen from the early 1600s, fuelling ironworks that ran into the 19th century, and in 1817 the Lough Allen Canal linked the lake to the main Shannon Navigation. In the 1920s the Shannon hydroelectric scheme turned it into a regulated reservoir, and sluices still manage the water levels today for flood control and dry-season supply. There’s a sporting streak too: yachts raced here from O’Connor’s Island and Birchill’s House in the mid-1800s, a tradition revived for one day in September 2015 when the Water Wags dinghy fleet came up from Dún Laoghaire.
Wildlife & Nature
Lough Allen’s clear, low-nutrient water holds pike – of the native Irish strain – along with perch and brown trout, making it a quiet but reliable spot for anglers. The surrounding wetlands are good for amphibians and dragonflies, and the rare orchid Irish lady’s-tresses (Spiranthes romanzoffiana) grows here, at one of only a handful of Irish sites for it. Birdwatchers regularly see great crested grebes, pochard and whooper swan, with bigger flocks arriving on autumn and winter migration.
Practical Information
The lakeshore is free to walk and open all year; the Adventure Centre’s activities and sauna are paid, and booked ahead. There’s free parking at the Adventure Centre, with a few roadside lay-bys along the R280 and R207 as well. The Miner’s Way is at its best from late spring to early autumn, when the days are longer and the paths drier.
Getting there – From Dublin it’s the M4/N4 to Carrick-on-Shannon, then the R280 north to Drumshanbo and the lake. Bus Éireann serves Drumshanbo; from the stop it’s a 1.5 km (20-minute) walk to the Adventure Centre, or a short taxi (around €10).
Accommodation – The Adventure Centre has its own hostel rooms and a campsite; beyond that there are B&Bs, self-catering cottages and hotels within a short drive, including the Landmark Hotel in Carrick-on-Shannon and Kilronan Castle. Book lodging and activities through the centre’s website.
Nearby Attractions
A short drive from Lough Allen opens up more of Connacht’s natural and historic highlights.
- Glencar Waterfall – a dramatic double cascade set in ancient woodland, just north of the lake.
- Lough Key Forest Park – features a canopy walk, puzzle trail and boat tours to Castle Island in Roscommon.
- Boyle Abbey – a well-preserved 12th-century monastic ruin with atmospheric cloisters and chapter house.
- Arigna Mining Experience – an underground tour of Ireland’s historic coal mine, a short drive from the eastern shore.