Imagine the echoes of hammers and the grit of granite dust. This is Krystalsøen. Not always a tranquil lake. It was once a bustling stone quarry on Hammerknuden.
Krystalsøen is a testament to Bornholm’s industrial past. It shows how nature reclaims what humans leave behind. Today its serene beauty belies its rugged origins.
In the 1800s the stone industry boomed here. A Copenhagen master mason named Wienberg leased this high ground. He started quarrying granite. Wienberg hired mostly Swedish workers. They found the winters cold and the summers hot. They nicknamed the quarry “Siberia”.
Imagine these men wielding hand tools. They split stone with sheer muscle. Straw mats offered some protection from the biting wind. Wienberg was later outcompeted. A German merchant named Martens acquired quarrying rights for 32000 kroner. His plan was ambitious. He wanted to supply granite for the Kiel Canal and German Baltic ports.
Martens went bankrupt in 1891. His brother-in-law Count Ohlendorff took over. Partnering with C.F. Tietgen they formed Bornholms Stenbrud. It was also known as Hammerværket. Modern technology arrived. Compressed air drills increased production. A large factory hall was built near the harbor. It had drop hammers for crushing granite.
The raw material came from the large quarry now known as Opalsøen. Granite blocks were transported by tipper trucks. They went to the stone railway down at the harbor. Back then Hammerværket employed about 1000 people.
World War I brought the operation to a halt. It briefly revived under Danish ownership. The industry never fully recovered. Hammerværket closed in 1972.
The name Krystalsøen refers to the water clarity. The water was once so clear. It sparkled like crystal. Today the water is more polluted.
Krystalsøen is one of the smaller lakes around Hammerknuden. Yet it is worth visiting. It is a reminder of the area’s granite quarrying past. The granite here was mainly broken by hand.
You can reach Krystalsøen various ways. Park at Hammeren Fyr and follow the path. You can also hike around Hammerknuden. The trail passes right by the lake. Another option is to walk up from Opalsøen. Follow the blue route past Gamle Dam.
In 1972 the Ministry of Defense sold the lake. It was sold to the Ministry of Tourism for 100 kroner. Old war plans turned into a vital tourist attraction.
Look closely at Krystalsøen. Consider its transformations. From a noisy quarry to a peaceful lake. Nature and history intertwine here. It offers a stunning view. Krystalsøen has even starred in films and TV series like “Rejseholdet”. A fight scene was filmed in the rocky landscape near the path to the lighthouse.