Walk onto Parys Mountain (Mynydd Parys) and you could be standing on another planet. The ground is streaked orange, ochre, rust, and acid yellow; the rock is bare and shattered; a single ruined windmill stands on the skyline. It looks like the surface of Mars — and it’s the result of one of the most extraordinary industrial stories in Wales.
A mountain that powered an empire
Copper has been dug here since the Bronze Age, but in the 1760s a huge shallow deposit was struck and Parys Mountain exploded into the largest copper mine in the world. For a few decades in the late 18th century it dominated the global copper trade, sheathing the hulls of Royal Navy ships and the bottoms of slave and merchant vessels alike, and turning the nearby port of Amlwch into one of the busiest harbours in Wales. The mountain was quite literally taken apart — what looks like a natural canyon is the hollowed-out remains of the mining.
What you’ll see
The colours are minerals: iron oxides and copper salts leaching from the rock, intensified by the acidic water that pools a vivid orange in the old workings. It’s a genuinely strange and beautiful landscape, and a magnet for photographers, especially in the low, warm light of early morning or late afternoon.
The waymarked circular trail (about 2 miles / 3 km) takes you around the Great Opencast — a vast amphitheatre of coloured rock — past ruined engine houses, the windmill that once pumped the workings, and viewpoints over the whole site. It’s a moderate walk on uneven ground with some ups and downs.
Practical notes
- Cost: free, with a free car park at the trailhead off the B5111 just south of Amlwch.
- Footwear: wear proper walking shoes or boots — the ground is loose, rocky, and uneven.
- Stay on the path. This is a former industrial site with unstable ground, deep shafts, and acidic water. Keep to the waymarked trail, keep children close, and keep dogs on a lead.
- Time: allow 1–1.5 hours for the circular trail.
- Don’t drink or paddle in the orange pools — the water is highly acidic.
Combine it with
Parys Mountain sits on Anglesey’s quieter north coast, near Amlwch. Pair it with the harbour at Amlwch Port (built on copper money), the Point Lynas lighthouse walk along the coast, or Cemlyn Bay and its tern colony to the west. It’s also a strong stop on a wider Anglesey ancient sites and history route, given the Bronze Age mining here.
It costs nothing, takes an hour, and looks like nowhere else in Wales — Parys Mountain is one of Anglesey’s most surprising hours.