Devil’s Punchbowl

Overview

The Devil’s Punchbowl sits high on the western slopes of Mangerton Mountain, just outside Killarney in County Kerry. At nearly 700 m above sea level, this glacial corrie lake is a classic remnant of the last Ice Age, carved into the mountain’s flank by ancient glaciers. The water shifts from an inky black to a striking turquoise depending on the light, and despite its depth and icy temperature, it rarely freezes solid. From the rim, walkers are rewarded with sweeping views over the Lakes of Killarney, Muckross House and Ross Castle, the MacGillycuddy’s Reeks, Dursey Island, Castlecove, and on clear days, the distant Dingle Peninsula and Kenmare Bay. The basin also serves as the headwaters for the Owengarriff River, which cascades down the valley to form the famous Torc Waterfall before joining Lough Leane. The entire area falls within the boundaries of Ireland’s National Parks, making it a protected landscape of significant ecological value.

History & Folklore

Long before geologists identified the basin as a glacial corrie, 18th-century observers like Arthur Young mistakenly described it as a volcanic crater. Today, the lake is better known for the tales that cling to its cliffs. The most enduring legend involves the local chieftain O’Donoghue Ross, who supposedly shared a meal with the Devil on Mangerton’s summit. When their conversation turned sour, O’Donoghue punched his host and fled down the mountain. In a fit of rage, the Devil tore a massive chunk from the peak and hurled it after the chieftain. The rock missed its target, landing in Lough Muckross to form Devil’s Island, while the missing piece left the deep basin we see today. A local variant claims the thrown stone became the Rock of Cashel. Another older tradition suggests the name derives from Poll an Ifrinn (Hole of Hell), while a lighter tale claims St Patrick trapped a serpent in the lake, freeing it only on Lá na Luain (Monday or Judgement Day).

By the 1840s, the Punchbowl was already a favourite stop for early tourists, who marveled at its “intensely cold” water and unfathomable depth. Locals even boasted that a drop of whiskey would make it “go down your throat like a torchlight procession.” Historically, the lake also played a practical role, supplying water to Killarney town and serving as a stronghold for the O’Donoghue clan.

Flora & Fauna

The upper slopes and surrounding heathland support a rich mix of native species. In summer, rocky outcrops host alpine lady’s fern, mountain avens, and rock cress, while bog cotton, purple heather, bilberry, dwarf willow, and crowberry carpet the lower and mid-level ground. The area is a stronghold for birdwatchers; ravens, kestrels, and peregrine falcons frequently circle the cliffs, and golden plovers and merlins can be spotted along the ridges. The occasional golden eagle has been seen soaring above the Reeks on calm days. Red deer and sika deer roam the higher pastures, and mountain hares are common in the winter months. The lake’s edge and the nearby Gortagullane River also attract dippers and other waterbirds.

Trail Details

Devil’s Punchbowl Loop

• Distance: 9.5–10.5 km
• Time: 3–5 hours (depending on pace and weather)
• Elevation gain: ~700–800 m
• Difficulty: Moderate to hard – steady climb with boggy, rocky sections
• Highlights: The opening section crosses Tooreencormick – site of a 13th-century battle between the MacCarthy and Fitzgerald clans – before the path climbs alongside the Finoulagh River. Views over Killarney National Park open at around 550 m. Dramatic lake views, frequent bird and deer sightings, alpine flora zones.
• Start point: Roadside parking at the concrete bridge near Molly Darcy’s Pub. The trailhead is clearly signposted, with a Kerry Mountain Rescue advice board beside the bridge. If the layby is full, some walkers park in the nearby village of Ferta and walk the 3 km approach road.

Mangerton Circular Trail

• Distance: ~13.7 km
• Time: 4–5 hours
• Elevation gain: ~980 m
• Difficulty: Hard – includes exposed ridges and longer cumulative ascent
• Highlights: Expands on the shorter loop to include the Horses Glen, where 400 m cliffs drop to Lough Erhogh and Stoompa Mountain looms beyond, plus Lough Managh, with panoramic views across the Black Valley and the Reeks.
• Start point: Mangerton Mountain car park off the N71 (approximately 6 km from Killarney town).

Both routes are well-marked, but conditions change quickly at altitude. The shorter loop is the most popular choice for day walkers, while the circular trail suits those seeking a full mountain experience.

Getting There

By car: From Killarney, take the N71 (Muckross Road) westward. Turn left at Molly Darcy’s Pub, then take the first right to reach the concrete bridge and trailhead. Parking is limited to a small layby beside the bridge and roadside spots; arrive early in peak season to secure a space. For the longer circular route, continue past the bridge to the dedicated Mangerton Mountain car park further up the N71.

Public transport: No regular bus service reaches the trailhead. The most practical option is a taxi from Killarney town (roughly a 10-minute drive). Visitors arriving by coach or train can easily combine a Killarney stop with a short taxi ride to the mountain base.

Facilities: Molly Darcy’s Pub at the trailhead serves hot meals, coffee, and snacks, making it a reliable spot to warm up before or after the walk. There are no toilets or shops on the mountain itself.

Seasonal Highlights & Weather

• Summer (June–August): Alpine flowers are in bloom, and the weather offers the best chance of clear visibility across the Reeks and Dingle Peninsula. Expect the most walkers during school holidays.
• Autumn (September–November): Heather turns deep purple and red, and the trails are noticeably quieter. Mornings are often still and clear.
• Winter (December–February): The lake takes on a stark, atmospheric quality. Trails can be icy or snow-covered, and winds are sharp. Only attempt the walk if you are experienced and properly equipped.
• Year-round note: Mountain weather shifts rapidly. Waterproof layers, a windproof jacket, and sturdy boots are non-negotiable.

Safety & Preparation

• Navigation: Fog frequently rolls over the summit ridge. Carry OS Discovery Map 78 and a compass, or download an offline GPS trail. The path is marked but can become indistinct in poor visibility.
• Footwear: Waterproof hiking boots are essential. The lower sections cross boggy ground that turns slippery after rain.
• Dogs: Permitted on both routes but must be kept on a short lead, especially near cliff edges and where livestock or deer may be present.
• Supplies: Bring enough water and high-energy snacks. Streams on the upper slopes are cold and not always reliable for drinking.
• Descent: Most accidents on Irish mountains happen on the way down. Maintain a steady pace and avoid rushing, especially on wet rock.
• Emergency: The Kerry Mountain Rescue advice board at the bridge outlines local protocols. Mobile signal can be patchy on the ascent, so let someone know your planned route and return time.
• Timing: Starting before 10am at weekends secures parking and gives plenty of daylight for the descent.

Practical Information

The Punchbowl walk is regularly featured in the Killarney Walking Festival, which offers guided routes and talks on the mountain’s geology and folklore. For downloadable GPX files, the ActiveME app and Hiiker platform provide user-updated trail data.

Start early, check the mountain forecast, and allow plenty of time to enjoy the descent. Most walkers agree the real reward is watching the light shift across the corrie as you make your way back down to the valley floor.