Archaeology news: 'Real rarity' of medieval crossbow bolts found at bottom of Danish lake

ARCHAEOLOGIST divers have uncovered an unexpected treasure trove of medieval crossbow bolts from the bottom of Lake Hammerso in Denmark.

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The discovery came as a total surprise to a team of Polish exploring the lake for much older artefacts. Lake Hammerso is the largest reservoir of water on the small island of Bornholm in the Baltic Sea, just south of Sweden. According to ancient traditions practised by the island's residents some 1,500 to 2,500 years ago, weapons taken from invaders would be ceremonially dumped into the island's lakes.

Lake Hammerso in the northeast corner of the island and near the ruins of Castle Hammershus seemed like the perfect candidate to find some of these weapons.

Professor Bartosz Kontny from the University of Warsaw's Department of Archaeology said: "The people living in Scandinavia 1,500 to 2,500 years ago practised the ritual destruction of weapons captured from invaders.

"The weapons were then thrown into the lakes during ceremonies."

The archaeologists led an expedition to Lake Hammerso this September, sending divers into the shallow waters.

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Archaeology news: Crossbow bolts in Hammerso lake

Archaeology news: A trove of medieval crossbow bolts was pulled from a Danish lake (Image: BARTOSZ KONTNY/PIOTR PEJS)

Archaeology news: Divers in Lake Hammerso

Archaeology news: The artefacts were pulled from Lake Hammerson on the island of Bornholm (Image: BARTOSZ KONTNY)

But rather than finding ancient treasures and weaponry, the archaeologists were greeted with a great deal of rubbish.

The bottom of the lake was littered with bottles, cans, coins and metal rods - likely from a nearby quarry.

And at the centre of Hammerso, they uncovered a modern-day bathtub, which they initially confused for a dugout canoe.

Professor Kontny: "At first we thought it was a dugout, which is a boat made out of one tree trunk.

"We were, therefore, counting on interesting finds from at least several hundred years ago.

This is a real rarity

Professor Bartosz Kontny, University of Warsaw

Luckily for the archaeologists, divers armed with metal detectors uncovered a trove of medieval crossbow bolts not too far from the lake's shore.

Lake Hammerso covers an area of about 24 acres and has a maximum depth of about 42ft (13m).

Professor Kontny said: "Near the shoreline in the northern part of the reservoir, over a distance of about 20m, we found medieval crossbow bolts from the 13th and 14th century.

"An interesting fact is that each of them had wooden shafts in the sleeves. This is a real rarity.

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Archaeology news: Crossbow bolt from Lake Hammerso

Archaeology news: The weapons have been dated to the 13th and 14th centuries (Image: BARTOSZ KONTNY)

"The belts are made in various types - both fastened with a sleeve and a mandrel driven into the wood."

So far, the archaeologists estimate the have only explored a fraction of the lake's bottom.

Alongside the bathtub and crossbow bolts, sonar scans have also revealed two sunken sailboats - likely from the 19th century.

And Professor Kontny believes many more secrets are waiting to be discovered in Denmark's lakes.

He said: "Almost no one dives in them and no archaeological research is conducted in them.

"In recent years, only we have dealt with this issue."

A similar search at the bottom of Hammerso was carried out by Polish archaeologists last year.

The researchers recovered a large fragment of a late medieval pole weapon.

The artefact measured more than 25 inches across and weighed in at about 2.2 lbs.

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