Overview
Coomasaharn Lake (Irish: Loch Chom Sathairn) sits roughly 4 km west of the coastal village of Glenbeigh, tucked into a valley hemmed in on three sides by steep mountain ridges. The lake’s dark, peat-stained water holds a glassy surface that reflects the sky and surrounding peaks with remarkable clarity. Enclosed by Coomreagh (593 m), Teermoyle (760 m), Coomacarrea (772 m) and Meenteog (715 m), the basin sits within the Reeks District, a recognised gold-tier Dark Sky Reserve. Entry is free, and while a quiet lakeside visit takes just an hour or two, the area is best experienced through its ridge walks, fishing spots, and starlit water activities.
History & Mythology
The Coomasaharn valley carries physical and cultural traces stretching back over 4,500 years. Archaeological surveys have identified ancient pathways dating to the Bronze Age, alongside later early Christian pilgrimage routes and medieval coaching roads that once linked inland farming communities to the coast.
Local landscape names preserve cycles of Irish mythology. The valley lies within the traditional hunting grounds of the Fianna, the legendary warrior band led by Fionn Mac Cumhaill. According to tradition, Fionn and his 500 Irish Wolf Hounds tracked deer across these ridges, and the nearby Seefin Mountain derives its name from Suí Fhinn (“the Seat of Finn”). The region’s deep mythic roots also connect to the origin of County Kerry’s Irish name, Ciarraí. Legend holds that Queen Maeve’s son Ciar founded the Ciarraige tribe, who eventually ruled the Killarney area.
Tangible evidence of this long occupation remains visible. Hikers passing through the valley can spot Bronze-Age rock-art panels and a mysterious ancient stone wall that traces parts of the ridge. Ogham inscribed stones on nearby Drung Hill further mark the landscape; visitors interested in similar early medieval monuments can explore the Ballintaggart site a short drive away.
Walking the Coomasaharn Horseshoe Loop
The primary reason visitors travel to this remote valley is the Coomasaharn Horseshoe Loop, a series of ridge walks that circle the lake. The route is traditionally tackled anti-clockwise, starting near the lake’s outlet. Three documented variations allow walkers to match the distance to their fitness and daylight hours:
| Route | Distance | Approx. Time | Main Peaks | Difficulty |
|---|---|---|---|---|
| Short Loop | 12 km | 4–5 h | Coomreagh, Teermoyle, Coomacarrea, Meenteog | Moderate |
| Medium Loop | 16 km | 6–7 h | Been Hill, Mullaghnarakill, Teermoyle, Coomacarrea, Meenteog, Knocknaman | Strenuous |
| Long Loop | 24 km | 8–10 h | All of the above + Macklaun Mountain (607 m) | Strenuous |
The trail follows exposed ridgelines and narrow cols, rewarding effort with 360° outlooks. To the north lie Dingle Bay and the sweeping sands of Rossbeigh and Inch Beaches. Westward views stretch to the Skellig Coast and Valentia Island, while the imposing massif of the MacGillycuddy’s Reeks dominates the eastern horizon. The steepest section crosses the arête between Teermoyle and Coomreagh; wet weather makes this stretch slippery, so grip and careful footing are essential.
Water Activities & Dark-Sky Stargazing
Coomasaharn Lake supports quiet recreational use. The waters hold brown trout, and local anglers frequently fish from the shoreline or small boats. The lake’s sheltered position also makes it suitable for kayaking and stand-up paddle-boarding. Because the area falls within a gold-tier Dark Sky Reserve, paddle-boarders and photographers often visit after dusk. With minimal light pollution, the Milky Way appears sharply defined, and the lake’s black surface doubles the night sky into a reflective canopy.
The lake also features in the Big Five Challenge, a multi-day adventure programme that includes a guided night-paddle leg. Participants must register in advance and collect a challenge passport from the Reeks District visitor centre in Killorglin.
Practical Information
Getting There & Parking
From the Ring of Kerry (N70), drive approximately 4.5 km west of Glenbeigh and turn left at the Coomasaharn Lake sign. Take the next right at the T-junction and continue 2.5 km on a narrow, unmetalled country road. A small roadside lay-by serves as the parking area. Space is limited and the road is actively used by local farmers, so arrive early in summer and always leave room for oncoming traffic.
Facilities & Nearby Amenities
There are no toilets, shops, or information boards at the lake. The nearest public facilities are at Rossbeigh Strand (roughly 5 km away) and in Glenbeigh village. Glenbeigh provides a selection of B&Bs, guesthouses, and traditional pubs where you can warm up and sample local Kerry produce.
Rossbeigh Beach makes an excellent post-hike stop, offering a long stretch of sand, a beach café, and safe swimming waters.
Navigation & Seasonal Tips
The Horseshoe Loop is well-trodden but lacks continuous waymarking. The ActiveME mobile app provides free GPS-enabled route maps, elevation profiles, and stage waypoints, which should be used alongside a physical map and compass. The walk is accessible year-round, but winter conditions bring snow and ice to the higher cols. Sturdy waterproof trekking boots, layered clothing, and a head torch (for early starts or late finishes) are strongly recommended. Check weather forecasts before attempting the medium or long loops, as cloud cover can reduce ridge visibility to near zero within minutes.