It is a popular - if remote - spot on the Norfolk Broads with an intriguing name.
For decades, boaters, anglers and ramblers have debated the origins of 'Dungeon Corner' to describe a picturesque bend where the Thurne makes an abrupt 90-degree turn.
The area, near the village of Martham, is surrounded by marshland with no obvious features to give a clue to its mysterious title - and certainly no evidence of dungeons.
But locals have now revealed the origin of the name.
They say it refers to a former use of the site, though nothing that relates to an underground prison.
David Sellar, 74, who lives nearby and regularly walks to Dungeon Corner, said: "It is a medieval term for 'meadow by the water' which has been corrupted into Dungeon Corner.
"It is a very lovely section, a great place to moor up, have a picnic, do some fishing and it is a somewhat secret location too."
By the 11th century, the marshes at Martham had dried out sufficiently for the area to become valuable hay-making meadows where sheep grazed.
Bullocks were used for ploughing and along with cows were taken to the meadows to fatten.
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In the 13th century on each side of the River Thurne were hay meadows, apart from a poor quality water-logged scrub land which was known as 'Dunsyn'.
Over the years, this became the more memorable 'Dungeon', as it remains.
The spot, close to Martham Broad, is one of the quietest on the Norfolk Broads because many boats are unable to reach it, as they are too large to pass beneath the nearby bridge at Potter Heigham.
But Dungeon Corner has near-legendary status among fishermen.
John Bailey, one of Britain's best-known anglers, has named it as one of his favourite spots describing it as a "Broadland paradise" which is "enthralling and enlightening" and a "joy".
It is also thought to be close to the location of the fictional Roaring Donkey pub from Arthur Ransome's children's classic, The Big Six, where the crew of the Death and Glory take an enormous pike they have caught nearby.
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The reason for the tight bend is thought to be because the original course of the Thurne continued in a straight line - along a now unnavigable waterway known as Hundred Stream - until it flowed out to sea between Winterton and Horsey.
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At some point, the river changed direction and it now flows down to the Bure, at Thurne Mouth. From Dungeon Corner, it goes into the nearby Martham Broad and West Somerton, the head of navigation.
The area around Dungeon Corner has a mysterious air that is only partly down to its odd name.
There are also tantalising - though widely debunked - reports that the remote area on the opposite bank was used during the Second World War as a secret airfield for ferrying undercover agents into occupied Europe.
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