Fort Prinzenstein
Kongensten's sister across the Volta, built a year later — and already half lost to the same sea.
Header Photo - at Richter Fort Osu, Accra
Ghana-Net.com · Greater Accra · Ada East · Ada Foah
Denmark built it in 1783 on the sand at Ada Foah, where the Volta meets the Atlantic. Britain bought it in 1850. The sea has taken it since. There is no fort to visit — only the beach where it stood, and a rubbish heap that archaeologists dug up before the waves could finish the job.
Kongensten — "the King's Stone" in Danish — was the Danish fort at Ada Foah, at the mouth of the Volta River in the far east of Greater Accra. It was small, it was built late, in 1783, and it has gone. The Ghana Museums and Monuments Board says it plainly: only traces may be found, and the fort "has since disappeared into the sea".
That makes this page different from most on this site. There is no building to describe, no ticket to buy and no guide to hire. What there is, is a clear warning about this coast — and a piece of careful archaeology done just in time.
The same fate, further east. Denmark's Fort Prinzenstein at Keta is going the same way, and much of it has already been lost. Kongensten shows where that ends.
By the 1780s Denmark was pushing east from Christiansborg at Osu, building posts along the coast to control the trade of the Volta.
The Volta was a highway into the interior, and Ada at its mouth was the gateway. The Danes built Kongensten there in 1783, in alliance with the people of Ada. The next year they fought the Anlo, Ada's rivals across the estuary, and afterwards built Prinzenstein at Keta. Both forts were part of the same push east — and both were used in the Atlantic slave trade.
Denmark's slave trade was banned from 1803, and its forts lost their purpose. On 15 March 1850 Britain bought Kongensten along with the other Danish possessions on the Gold Coast. Like Fredensborg at Old Ningo, it was a fort nobody needed any more.
The coast at Ada is low, sandy and moving. Ghana's shoreline has retreated by around 110 metres in places, and the Volta estuary is among the most exposed stretches of all. Houses, roads and whole parts of Ada Foah have been lost over the last decades.
Kongensten stood on that sand. Over time the waves undercut it, and the fort was washed away. A University of Ghana study describes it as "totally eroded away by the rising sea water".
This is the future of more than one fort. Prinzenstein at Keta and several ruins along the eastern coast stand on the same kind of ground. Nobody was able, or willing, to save Kongensten. The question is whether anyone will act before the sea takes the next one.
The only serious record of Kongensten on the ground comes from archaeology done in a race against the sea.
In a 2015 MPhil study at the University of Ghana, V. A. Aryee used salvage archaeology, archive work and interviews to document what was left at the fort site before it disappeared completely. The excavation found a midden — a rubbish heap — holding local pottery, European ceramics, the stems and bowls of clay smoking pipes, cowrie shells, glass bottles, pieces of metal, and large quantities of shells from the lagoon.
Those finds are what remains of daily life at Kongensten: what the Danes and the people of Ada ate, drank, smoked and traded. They are now the fort's only surviving evidence.
Credit where it is due. This page criticises how Ghana's forts are looked after. The salvage work at Ada is the opposite: Ghanaian archaeologists documenting a site before it vanished. It deserves to be better known.
East past Tema along the coast road towards the Volta. Ada Foah is roughly two hours from central Accra, more when the Tema traffic is bad.
Trotros run from Accra and Tema to Ada. Ask for Ada Foah, and in town ask the older people where the Danish fort stood.
The beach and the sea where the fort once was. The Volta estuary and its islands are the real reason to come to Ada.
The Volta estuary, Fort Fredensborg at Old Ningo and Fort Vernon at Prampram on the way, Shai Hills inland.
When to go. Ada's great festival is Asafotufiam, the march of the warrior companies. Hotels along the estuary on ghanahotels.biz; beaches on Greater Accra Beaches. More on the capital: Accra.
No tour goes to Kongensten — there is no fort left to go to. The tours below cover the castles that still stand, at Cape Coast and Elmina.
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Kongensten's sister across the Volta, built a year later — and already half lost to the same sea.
The Danish "fort of peace", built for the slave trade and handed to Britain as a ruin in 1850.
The British post at Prampram, now nearly invisible, used as a warehouse at the beach.
A Danish plantation fort, part of Denmark's late attempt to grow crops rather than ship people.
Denmark's headquarters on the Gold Coast, later the seat of Ghana's government.
Where Ghana's great river meets the Atlantic — the reason the Danes came to Ada, and the reason to come now.
All of them, in order: Forts and Castles of Ghana.
You cannot visit Fort Kongensten. You can stand on the beach at Ada Foah and see why: the sea that took it is still coming. Kongensten is the first fort on this coast to be lost completely to the water. Unless something changes at Keta, it will not be the last.
Verified: 26 September 2026. Danish construction in 1783, British purchase on 15 March 1850 and the fort's disappearance into the sea are as stated by the Ghana Museums and Monuments Board. The shoreline retreat, the fort's total erosion and the midden finds come from V. A. Aryee, Salvage Archaeology at the Fort Kongensten Site of Ada Foah, MPhil thesis, University of Ghana, 2015. The link to the Danish–Anlo conflict of 1784 and the building of Prinzenstein follows standard accounts of the Danish Gold Coast. Corrections welcome and will be published in full.