The area we use for the zipline has a story to tell. Read it here.

Perhaps the largest and most impressive rock quarry on Bornholm, the Hammeren Granite Works, was established in 1873 by a German wholesaler named Martens, who purchased the property from the Municipality of Allinge-Sandvig.

The business didn’t do very well, however, and it was rented to R.A. Wiinberg. But in 1891 the quarry was sold to Wiinberg’s brother-in-law, the German baron V. Ohlendorff.

With Tietgen as middleman and figurehead, the company known as the Bornholm Granite Works was established.

The business grew quickly, at times employing several hundred men, including many Swedish immigrants. In 1892 the Hammer Harbor was established at Sæne Bay to ship out quarry products, especially stones bound for the Kiel Canal in Germany.

Apart from the large industrial plant, a number of homes were built for the director, the administrators and, in Sandvig, two long rows of houses for the quarry workers.

The First World War put a stop to the German-owned company, which had also owned the entire Hammer Promontory. An initiative started and supported by the people of Bornholm resulted in the area being nationalized in 1914.

Due to the natural beauty of the area, the residents of Bornholm, led by Prefect Valløe, wanted to close the quarry and ensure that it remained in Danish hands.

The State rented the area out to A/S Møller and Handberg, who increased the quarry activity. A large stone-chipping plant was built in 1927-28, and in 1930 a large loading dock was built at Sæne Harbor. In 1941, the company changed its name to A/S Vald.

Handberg’s Stonemasonry and Quarry took over the Moseløkken quarry near Hammeren. The Moseløkken quarry  had been established by a couple of businessmen in the 1870s and was later successfully run by local owners who produced high-quality stone that was used to create the pillars of the Danish National Museum and the stone elephants at the Carlsberg Brewery.

When the Hammer quarry closed, Moseløkken was taken over by “The United”, which still extracts stone there. The large Hammer quarry was slowly phased out, and the entire area was cleared by the State in the 1970s.

On Northern Bornholm, there were a number of quarries in the 1800s and 1900s. Among the largest was the quarry south of Vang near the coast, and another one further south in the Ring Hills (In Danish: Ringbakkerne) near the coastal cliffs. Vang Granite was established in 1896 and continued until 1973.

The stone industry was and still is a major industry on Bornholm, although today it employs much fewer people than before.

After the Hammer quarry closed

A sensational event occurred in 2005, when the peregrine falcon returned to its old breeding grounds on Bornholm after an absence of more than 50 years.

A pair was found making its home at the old Hammer quarry.

The Forestry District cordoned off the area so that the returning birds could establish themselves in peace.

However, there was much popular demand for recreational use of the area, and the authorities had to give up the barrier and allow various types of extreme sports.

Early in the breeding season, peregrine falcons have several times shown interest in the former quarry, only to retreat and then successfully establish themselves at the Hammer Cliffs and Razorbill Ravine (in Danish: Mulekleven), both of which are also former breeding grounds.

Today, the area around Opal Lake is a destination for outings, hikes and extreme sports. All activities take place in accordance with Danish Nature Agency requirements.

Rumor has it that Opal Lake is 50 meters deep – and there are also rumors that some quarry machinery is still down there at the bottom somewhere. It’s not true.

We’ve spoken to a former employee who was there when the quarry closed down. He told us that there is no machinery down there. The bottom was in fact filled up with granite chips, so the entire lake has a depth of just 10 meters.