Rubinsøen (Ruby Lake) – former coal mine and peaceful lake near Hasle
Rubinsøen (Danish for “ruby lake”) was an open-cast lignite mine just south of Hasle — today a calm, wooded lake surrounded by steep slopes and forest paths. An easy, free outing: a walk, a picnic with views over the water, or a quiet moment away from the beach crowds. The mix of Second World War history and natural landscape makes Rubinsøen one of the distinctive spots on western Bornholm.
Former coal mine from wartime years
The lake formed in the pit left after lignite (brown coal) was extracted south of Hasle. During World War II it was hard to secure fuel for Bornholm’s industries, so more than 30,000 tons of brown coal were mined here between 1942 and 1948. When work stopped, the pit filled with water — today Rubinsøen bears a poetic name evoking the ruby gleam of the surface. Steep slopes and pine forest surround the site; nearby you can also see other former mining ponds — Safirsøen, Smaragdsøen and Pyritsøen — forming the characteristic “mining landscape” of western Bornholm.
Martian landscape of Kultippen near the former mine lakes
Kultippen – landscape south of Hasle
Picnics, walks and forest paths
Rubinsøen is an obvious spot for a relaxed picnic. Forest paths run along the steep slopes that ring the former coal pit, and higher up — on the rim of the bluff — wooden tables and benches have been placed. From here you look out over the water; in autumn wild blackberries (brombær) ripen along the woodland tracks — worth bringing a basket for a taste of local flavour.
Access is at your own risk: there are no gates or entry fees, and dogs are welcome. Marked walking routes cross the area, and an information board by the lake tells the story of the site.
Fishing and practical information
Rubinsøen is also popular with anglers — the lake holds a sizeable pike population, and the fish can grow large. Coarse fishing works well too; according to tourist information no fishing licence is required. A calm afternoon after a day at Hasle beach, or a brief stop on a hike along the west coast.
- Marked walking routes in the forest above the lake
- Information board at Rubinsøen
- Picnic tables and benches on the bluff above the water
- Free access; dogs allowed
- Good fishing spot (pike) – no fishing licence required
Nearby: Kultippen and other “mining lakes”
South of Hasle lies the area of former workings — including famous Kultippen with its “lunar” landscape and a group of vividly named lakes: Safirsøen, Smaragdsøen and Pyritsøen. Rubinsøen belongs to the same post-industrial nature scene that today attracts walkers and photographers.
Next to Rubinsøen lake lies Safirsøen
Good to know about Rubinsøen
- Former open-cast lignite mine; more than 30,000 tons of brown coal extracted between 1942 and 1948
- Today a flooded pit — a calm lake surrounded by steep slopes and forest
- Free access; dogs allowed; tables and benches by the shore
- Popular for picnics and fishing (pike); no fishing licence required
- Location: Sorthat, 3790 Hasle – about 2 km south of central Hasle
Lokalizacja
| Rubinsøen | |
| Fælledvej, 3790 Hasle | |
| The lake lies in the Sorthat area, south of Hasle. Reach it on foot or by bike along forest roads from the town; marked routes lead around the pond. | |
| No large car park directly at the lake — it is easiest to leave your car in Hasle (e.g. at the harbour) and walk or cycle in. |
