
Lough Arrow SAC is a protected area centered on a large limestone lake known for its rich biodiversity, including rare aquatic plants and species; it offers exceptional opportunities for tranquil nature observation, fishing, and birdwatching.
Lough Arrow SAC is a designated Special Area of Conservation located primarily between County Sligo and County Roscommon in the west of Ireland. The central feature is Lough Arrow, a large, deep, marl-rich lake formed in a limestone basin with clear, nutrient-poor waters. The lake and surrounding habitats support a diverse array of wetlands, grasslands, and woodland ecosystems. Notably, Lough Arrow provides habitat to many rare and protected species, including the slender naiad (Najas flexilis), a rare aquatic plant listed under the EU Habitats Directive. The SAC also supports populations of otters (Lutra lutra), freshwater pearl mussels, and various species of butterflies and birds, making it an important biodiversity hotspot in the region.
The area has a rich historical and cultural backdrop, with ancient settlements, ringforts, and archaeological sites near the lakeshore. Visitors are drawn to Lough Arrow for peaceful outdoor recreation such as angling (particularly for brown trout and pike), birdwatching—where species like the whooper swan and great crested grebe can be seen—and hiking around the lake’s scenic shoreline. The lake is surrounded by gentle hills and small patches of woodland and scrub habitat, providing picturesque perspectives for photographers and nature enthusiasts. While there are no officially marked long-distance trails within the SAC itself, local footpaths and quiet country roads allow access to various viewpoints.
Lough Arrow’s conservation interest lies heavily in maintaining its pristine aquatic environment and associated habitats. Preservation of water quality in this largely unpolluted lake is vital. The SAC attracts visitors who appreciate tranquil natural beauty in a less commercialized setting compared to larger national parks, offering an off-the-beaten-path experience in western Ireland's unique limestone landscape.
Lough Arrow - a large, clear, marl-rich lake famed for its aquatic biodiversity
Habitat for slender naiad, a rare and protected aquatic plant species
Birdwatching opportunities featuring whooper swans and great crested grebes
Historic lakeside archaeological sites including ancient ringforts
Lough Arrow is one of the few Irish lakes where the rare slender naiad, an underwater aquatic plant, thrives in the marl-rich waters.
The clean waters and good substrate of the lake support populations of the endangered freshwater pearl mussel.
The lake shores feature remnants of ancient ringforts and settlements, revealing the long historical human presence in the area.