Mynydd Allt-y-grug

About Mynydd Allt-y-grug

Perched above Ystalyfera, this twin-peaked hill is a bit of a drama queen. Its eastern flank is a chaotic jumble of landslides and prickly flora, while the heather-clad summits offer surprisingly grand views of the Swansea Valley—provided you survive the aggressive gorse.

Key Statistics

Find It

Did You Know?

• •The hill is a geological rebel, featuring an unstable eastern slope notorious for historic landslides that have kept the residents of Ystalyfera on high alert for generations.
• •You get two for the price of one here; the hill boasts twin summits roughly 400 metres apart, doubling your chances of walking to the wrong one first.
• •While its name translates to 'Heathery Hill Wooded Slope,' the western side is a far more orderly affair, cloaked in a neat, industrial-looking blanket of conifers.
• •The drainage from these slopes feeds directly into the River Tawe, making the hill a vital, if somewhat soggy, contributor to the Swansea Valley's hydrological cycle.
• •Navigating the eastern side is less of a pleasant stroll and more of a tactical wrestling match with brambles and gorse that seem personally offended by your expensive waterproofs.