Holywell Hill | Donegal

Overview

Holywell Hill (Irish: Cnoc an Tobair) rises 260 m (853 ft) above sea level on the Inishowen peninsula in County Donegal. It is the highest point in the Holywell Hills range and the most southerly summit on the peninsula. The hill sits just 50 m from the border with Northern Ireland, giving uninterrupted views across both jurisdictions. Its Irish grid reference is C385171 and the site lies in the townland of Loughros Glebe, electoral division of Glenalla, civil parish of Tullyfern.

The hill is best known for the 60 m self‑supporting steel lattice transmission mast owned by 2RN (formerly RTÉ NL). Erected in 1981, the mast originally improved UHF TV reception for north‑west Donegal and Derry City and now carries Saorview digital television and five national FM radio services.

Archaeology and Early History

Historical sources (Mabel R. Colhoun, The Heritage of Inishowen; Brian Lacey, Archaeological Survey of County Donegal) record a holy well and a megalithic cairn on the summit. The cairn, about 40 ft (12 m) in diameter, encloses a stone‑lined cist that once collected rain‑water believed to have special qualities – the origin of the hill’s name, Cnoc an Tobair (“hill of the well”).

At the summit you will find the remains of the cairn described by the 1983 County Donegal survey: a low earth and stone mound with a central cist measuring roughly 1.5 m × 0.85 m. The cist’s stone slab roof is now tilted inward under the weight of the surrounding stones. A small pool of rainwater once collected in the cist and was regarded locally as a holy well, giving the hill its name.

Early‑medieval references suggest the hill lay on the boundary of the ancient kingdom of Cenél nÉnnai and may have served as a landmark for inauguration ceremonies of local chieftains. The hill was recorded by 17th‑century English surveyors as Knockena, likely a reflex of Cnoc Énna.

Elevation, Prominence and Rankings

While the official OS map lists the summit at 260 m, the PeakVisor database records an elevation of 313 m (1 027 ft) and a prominence of 295 m, ranking Holywell Hill #23 of 343 peaks in Northern Ireland and #27 of 512 in County Donegal. The difference stems from varying survey data; both figures are cited by reputable sources.

The hill’s prominence makes it a popular target for peak‑baggers, and the site is marked on the MountainViews database (summit 992) and the PeakVisor 3‑D map.

Naming and Historical References

The Irish name Cnoc an Tobair translates as “hill of the well”, directly referencing the holy well within the cairn’s cist. Historical documents also list the anglicised form Knockena, derived from the older Irish Cnoc Énna.

Scholars such as Brian Lacey have linked the hill to the ancient territorial limits of Cenél nÉnnai, suggesting it may have been a ceremonial viewpoint for early kings of the region, although its exact ritual use remains speculative.

Access & Parking

Holywell Hill is reachable by car via the B193 (Derry – Newtown Cunningham) and a minor road signed L2013 that turns off just west of Killea. Follow the road for about 2 km to a gated access road for the mast; a small lay‑by provides free parking for a few cars. The gate can be opened and the path continues onto the well‑maintained walking track.

Public transport options are limited; the nearest bus stop is in Killea, with services to Derry and Buncrana. From there, a short taxi ride or a walk of 1 km brings you to the trailhead.

Walking routes & Trig Pillar

The main footpath to the summit is a gentle, grassy track suitable for most walkers. The round‑trip is roughly 3.4 km with an ascent of about 174 m and can be completed in under an hour. For those seeking a longer hike, the PeakVisor app suggests alternative loops ranging from 4.1 km (197 m ascent) to 6.1 km (243 m ascent).

At the top, the transmission mast dominates the skyline, but the surrounding open heath offers excellent photographic opportunities, especially during sunrise (≈06:36‑08:06) and sunset (≈19:02‑20:32). The trig pillar and the unmarked MV high‑point provide additional landmarks for navigation and for those collecting Irish summit points.

Panoramic Views

From the summit you can see the Atlantic coastline, the Inishowen hills, and on clear days the distant peaks of Slieve Snaght (615 m). The Grianán of Aileach stone fort lies a short distance to the east and is visible on a clear day. To the north‑west the rugged outline of Greenan Mountain and its ancient cashel are prominent.

Broadcasting Heritage

Enthusiasts of Irish broadcasting can view information panels near the summit that explain the evolution from analogue to digital transmission and list current TV and radio frequencies.

Practical Information

Access – Reachable via the B193 and minor road L2013; free lay‑by parking near the trailhead.

Walking routes – Main 3.4 km loop; optional longer loops via PeakVisor. The path is sign‑posted and suitable for most walkers.

Maps – OSNI 1:50 000 Discoverer Series Sheet 7 (grid reference C385171). The hill also appears on the MountainViews database and on the PeakVisor 3‑D map.

Broadcast services –

Service	Frequency	ERP	Type
Saorview 1	482 MHz	22 kW	Digital TV
Saorview 2	506 MHz	25 kW	Digital TV
RTÉ Radio 1	89.2 MHz	6 kW	FM Radio
RTÉ 2fm	91.4 MHz	6 kW	FM Radio
Raidió na Gaeltachta	93.6 MHz	6 kW	FM Radio
RTÉ lyric fm	98.8 MHz	6 kW	FM Radio
Today FM	101.0 MHz	6 kW	FM Radio

Seasonal considerations – Open year‑round; no formal opening hours or seasonal restrictions. The exposed position can be windy, so sturdy footwear is recommended.

Nearby attractions – The Grianán of Aileach stone fort, Greenan Mountain with its ancient cashel, and the coastal drive along the Wild Atlantic Way. The village of Burt and its distillery are also within easy driving distance.