Lough Gowna and Sonnagh Fort

Overview

Lough Gowna (Loch Gabhna) straddles the Longford‑Cavan border, its 1,800‑acre (728 ha) surface formed by a moraine dam at the close of the last glaciation. Shallow, weed‑laden waters (2‑8 m, up to 15 m near Dring) wind through a classic drumlin landscape, fed by the River Erne at Derries Lough and draining northward back into the Erne. Overlooking the lake from a drumlin ridge to the east is Sonnagh Fort, a rare bivallate ringfort that offers panoramic views of the lake and surrounding plains.

Location & Access

Lough Gowna lies about 12 km north‑west of Longford town. The main access points are the public launch sites at Dernaferst, Lisanny and Dring on the Longford side, and Cloone, Aghanoran and Corfree on the Cavan side. Each site provides a gravel slipway and limited parking; the nearest larger car parks and restroom facilities are in Ballinalee and Aughnacliffe. The ringfort sits roughly 1.2 km west of the lake’s shoreline and is reachable via a short, well‑maintained footpath from the Dernaferst launch area.

History & Heritage

Lough Gowna

The lake’s name stems from a local legend of a supernatural calf that fled from a well in Rathcor, carving the waterway that became the lake. Its most striking historic feature is Inchmore (Inis Mór), a sizeable island in the south‑western arm. Saint Colmcille founded a monastery there in the sixth century; Vikings raided it in 804, Augustinian monks re‑established it in the twelfth century, and Henry VIII dissolved it in 1543. Stone ruins still mark the island, and a fifteenth‑century bell recovered from the site now hangs in Aughnacliffe’s Roman Catholic church.

Sonnagh Fort

Sonnagh Fort (Ráth an tSonnaigh) is a National Monument and the best‑preserved of seven ringforts that once encircled Aughnacliffe. The bivallate enclosure – inner bank 0.5‑0.9 m high, outer bank up to 1.9 m – spans roughly 46 m in circumference and covers 0.39 ha (0.96 acres). It dates to the Bronze or Iron Age (c. 2400 BC – AD 400) and is privately owned but protected by the State through the Office of Public Works (OPW). A natural spring lies immediately to the east, providing water to the early medieval inhabitants. The Irish word sonnach means “palisade”, a reference to the fort’s double bank and ditch.

Activities & Recreation

Fishing

Renowned as one of Europe’s premier coarse‑fishing lakes, Lough Gowna yields pike year‑round, with peak catches in March‑May and September‑November. Anglers also target perch and roach, especially from the boat‑access points that reach the weed‑rich shallows.

Boating, Kayaking & Paddle‑boarding

The lake’s calm bays are ideal for small craft. Kayaks and paddle‑boards can be launched from any of the public slipways, offering a quiet way to explore hidden inlets and the island of Inchmore.

Walking, Wildlife & Picnic

Well‑maintained pathways trace the lake’s intricate shoreline, weaving through planted woodlands, peat‑bog fringes and wildlife sanctuaries. Birdwatchers may spot mute swan, whooper swan, wigeon and a range of waders. Families enjoy picnics beside tranquil bays, with the spring at Sonnagh Fort adding a gentle soundscape.

Sonnagh Fort Exploration

Visitors can wander the open‑air site to appreciate:

• The double bank and ditch that define the fort’s defensive strength.
• The 4 m wide southeast entrance, hinting at controlled access.
• The spring to the east, a natural water source.
• Panoramic vistas of Lough Gowna, the drumlin countryside and the plains toward County Westmeath. The surrounding wetlands also attract birds, adding a natural soundtrack to the historic ambience.

Nearby Attractions

A short drive brings you to the historic village of Aughnacliffe, where the bell from Inchmore’s monastery hangs in the parish church. The market town of Ballinalee offers cafés, a heritage centre and additional parking for lake visitors. For a broader lakeside experience, consider the Longford Lakeside Recreation Areas, which include walking trails and water sports facilities.

Practical Information

• Access: Both Lough Gowna’s launch points and Sonnagh Fort are free to the public. The fort is unguided and has no on‑site facilities; the nearest parking, restrooms and refreshments are in Ballinalee or Aughnacliffe.
• Management: Sonnagh Fort is owned by the State and managed by the Office of Public Works (OPW). The lake’s amenities are maintained by local councils.
• Opening Hours: Open year‑round, unrestricted access; launch sites operate year‑round, though weather may affect boating.
• Visitor Tips: Bring a boat or kayak for fishing, wear sturdy shoes for the ringfort’s earthen banks, and pack a picnic to enjoy the lakeside scenery.
• Safety: Observe local fishing regulations, stay on marked paths, and respect the archaeological site’s fragile earthworks.

Enjoy a day that blends angling, gentle walks, and a step back into Ireland’s early medieval past, all set against the tranquil backdrop of Lough Gowna.