Smaragdsøen (Emerald Lake) – green water and the first clay pit near Hasle
Smaragdsøen (Danish for “emerald lake”) is one of the best-known ponds in the Hasle area on western Bornholm — a woodland lake in a former clay pit whose water often takes on a slightly green, emerald-like hue. Clay extraction for the local brick and refractory factory began here in the early 20th century; today Smaragdsøen blends industrial history with pine forest calm, proximity to the sea and neighbours such as Pyritsøen, Safirsøen and Rubinsøen.
The factory’s first clay pit — and the spring that stopped the work
When Hasle Klinker- og Chamottestensfabrik started up around the turn of the century, the first clay pit was dug where Smaragdsøen lies today. The clay was suitable for brick and clinker production, but a strong spring at the bottom of the pit made further deepening almost impossible — water pushed up with such force that work had to be abandoned. Extraction moved south to what is now Pyritsøen, which supplied the factory for decades until it closed. The Smaragdsøen pit later filled naturally; Baggeå was also routed through the lake, linking the forest pond to the stream network flowing towards the coast.
Forest, beach and quiet walks by the sea
Smaragdsøen lies close to the shoreline in Hasle Klinker Skoven (Sandflugtsskoven) — a fine setting for a short walk between lakes or a pause in the shade of pines. There is also a small sandy beach nearby where you can relax by the sea on warm days after a woodland stroll.
The lake shores themselves are often steep and tree-lined, so access to the water is not always easy — more a place for landscape and quiet nature than mass recreation at the water’s edge. Marked footpaths in the area link the colourful former pits of western Bornholm.
Fishing — rich waters, but a licence is required
Smaragdsøen is prized by anglers for varied fish life: roach, eel, perch and pike occur here, and in autumn sea trout may enter from Baggeå. Fish can grow larger than in some neighbouring ponds, yet fishing is not straightforward — steep, shaded banks make access awkward. Unlike Rubinsøen or Safirsøen, a Danish fishing licence (fisketegn) is required on Smaragdsøen — available online at fisketegn.dk.
- Fishing licence (fisketegn) required on Smaragdsøen
- Possible catches include pike, perch, eel, roach; sea trout in autumn from Baggeå
- Steep, wooded shores — less convenient pegs than on open lakes
- Baggeå flows through the lake; the stream reaches the coast near Hasle
- Free land access; angling subject to Danish regulations
Nearby: Pyritsøen, Safirsøen and other Hasle lakes
Smaragdsøen forms a chain with Pyritsøen, Safirsøen and Rubinsøen — former workings west of Hasle. Forest paths run between Smaragdsøen and Pyritsøen; combine both lakes in one outing, then continue south to Safirsøen, Rubinsøen or surreal Kultippen.
Footpath between Smaragdsøen and Pyritsøen in Hasle Klinker Skoven
Good to know about Smaragdsøen
- First clay pit for Hasle Klinker- og Chamottestensfabrik (c. 1900) — halted by strong groundwater
- Name from the greenish surface; woodland lake despite Baggeå flowing through
- Angling: fisketegn required; pike, perch, autumn sea trout
- Close to the sea and a sandy beach; Hasle Klinker Skoven / Sandflugtsskoven
- Location: Sorthat, west of Hasle — beside Pyritsøen, Safirsøen and Rubinsøen
Lokalizacja
| Smaragdsøen | |
| Havvej, Sorthat, 3790 Hasle | |
| The lake lies in forest west of Hasle in the Sorthat area, near the coast. Best reached on foot or by bike from Hasle; paths link it with Pyritsøen. | |
| No large car park at the lake — leave your car in Hasle and walk in on forest paths. |
