Walking through Middelalderparken with guide Sara from Oslo Ladegård is a walk between two men who once ran this city: the bishop, who governed from the north end of the park, and the king, who governed from the south. It takes ten minutes to cross the distance between them today. In the eleventh century, that distance contained the entire town.
It is also a walk through a story that keeps rewriting itself. In May 2026, researchers from the Norwegian Institute for Cultural Heritage Research (NIKU) announced that a mound beneath Oslo's royal manor – long assumed to be part of the king's medieval building works – was in fact a boat grave from the late Viking Age, carbon-dated to around the year 1000. The manor, it turns out, was built on top of someone else's monument.
The bishop's castle that isn't there
The walk starts at a handsome brick building does not belongsto the Middle Ages. It doesn't. The building — known as the "baroque house," Oslo Ladegård — was built in 1725. What is medieval is underneath it: the foundation walls are the remains of the bishop's castle, a stone fortress with four wings, each two storeys high, built through the 1200s.
The bishop who commissioned it was one of the most powerful men in the city. His castle would have dominated a townscape that, by the standards of the time, was tiny — Oslo's medieval built-up area was roughly the size of today's Slottsparken, the palace grounds. At its height, perhaps 3,000 people lived there. A brisk walk from where the bishop's castle stood to the mouth of the Alna river, at the opposite edge of town. It takes about ten minutes on foot.
Directly across from the castle stood the bishop's own cathedral, St. Hallvard's, dedicated to Oslo's patron saint and, by most estimates, one of the largest buildings in the medieval town. A right-of-way is thought to have connected castle to cathedral directly, so the bishop could walk from his residence into his own church. Gamle Aker Church, still standing today north of the city center, is often cited as a smaller-scale echo of what St. Hallvard's may have looked like, since no trace of the cathedral itself survives above ground.
What a street can tell you
The path south from the bishop's quarter follows Vestre Stræte, one of the medieval streets whose route archaeologists have been able to place with unusual confidence.
That confidence is rare in this line of work. Written sources from Oslo's medieval centuries are thin — most residents could neither read nor write, and Norway had little tradition of the landscape painting that, elsewhere in Europe, incidentally recorded how towns looked.
So much of what is known about medieval Oslo comes not from documents but from digging, and from what is sometimes called "qualified guesswork": street names, church dedications and the physical layout of ruins used to infer things no one wrote down.
Excavations along this street uncovered timber roadways and the foundations of houses packed close together — evidence, guides explain, that these routes needed to be wide enough for carts, exactly as a town law from 1276 specified. That law, issued by King Magnus Lagabøte for Oslo, Bergen, Tønsberg and Nidaros, turns 750 this year, and Oslo is marking the anniversary with public lectures through the autumn.
None of the original timber survives on site, and that is also a story about method. Wood buried for centuries in oxygen-poor, waterlogged ground survives remarkably well — until it is dug up. Once exposed to air, it decays rapidly unless kept permanently wet. So archaeologists record it, photograph it, and remove it, rather than risk a later excavation misreading a re-buried structure as something older or newer than it is.
What visitors see today in the reconstructed timber houses further along the route is a modern echo, built in recent years by 1,500 Oslo schoolchildren using only the tools available in the Middle Ages — axes, drawknives, no saws.
Oslo's birthplace
South of the church street, the park opens onto an artificial reflecting pool, laid out for the city's millennium celebrations in the year 2000 to mark the former harbor line. It sits near what archaeologists have called, only half-jokingly, Oslo's birthplace: graves found near the ruins of St. Clement's Church, radiocarbon-dated to roughly 980–1030. Some of the dead were women and children, which tells its own story — this was a settled community, not just a seasonal trading post.
For a long time, Oslo's founding was dated to around 1050, tied to a written reference to Harald Hardrada establishing a kaupstad, a market town, here. The Clement's Church graves pushed that date back by decades, and Oslo marked the revised anniversary with its millennium celebrations in 2000. The boat grave discovery announced in 2026 pushes the story further still, suggesting this stretch of shoreline mattered as a place of power before anyone thought to call it a town.
Life at the waterline
Where the harbor once was, long piers would have reached out into shallow water — the fjord here was only a couple of metres deep close to shore, hardly ideal for a trading port, which is presumably why the piers needed to be so long. Simple timber warehouses, sjøboder, stood at the water's edge; two have been reconstructed nearby, built in the same laft technique — interlocking horizontal logs — used throughout the medieval town, and designed, like the original buildings, to be taken apart and moved.
Archaeologists nicknamed this waterfront district "the slum," on the evidence of smaller, rougher house remains than those found further inland. This was the working end of the medieval town: craft, trade, noise, and — near-certainly — smell, which residents would barely have noticed and modern visitors would not have tolerated for a day. Streets were washed twice a year, at Christmas and Easter. Grain, the staple food, was imported along with meat for wealthier households, timber went out by the shipload, and analysis of medieval latrines has told archaeologists what people actually ate: dried figs and imported wine among the well-off, parasites among those who ate spoiled meat more often than they'd have liked. Nobody drank from the rivers. Wine, beer and soured milk did the job water does today, since the town had no way to purify what ran through it — though every household was legally required to keep a barrel of river water indoors, in case of fire. Given that Oslo burned down, in whole or in large part, somewhere between fifteen and twenty-five times across five or six centuries — roughly once a generation — the barrels cannot have been enough.
The king's church, and the queen who arrived to build alliances
At the southern tip of the park stood the second center of power: the king's manor and his own church, Mariakirken, begun as a simple wooden chapel around 1050 and rebuilt over the following centuries into one of the town's grandest buildings, reportedly some 40 metres tall. From 1314, Oslo's status as the kingdom's capital was formalized when King Haakon V made the chancellor of Oslo permanent royal chancellor — a decision made a few hundred metres from where his own grave was later found.
That grave, in the church choir, was first disturbed in the 1860s, when the skulls now identified as those of Håkon V and his queen, Eufemia of Rügen, were removed during early excavation and sent to the university. It took until 1975 for researchers to confirm whose remains they were; in 1982, they were reburied in the crypt at Akershus Fortress. A third grave nearby belonged to Eufemia's father, Wizlaw II of Rügen, who died suddenly while visiting his daughter and son-in-law at Christmas in 1302 — an oddly personal footnote at the heart of a royal church.
Eufemia had arrived from northern Germany in 1299 to marry a duke who was not expected to inherit the throne; his brother's death without an heir made him king, and her queen, within three years. She is remembered less for politics than for the library she is said to have brought with her: three surviving verse romances, the Eufemiavisene, credited with helping launch a literary tradition in neighboring Sweden. Dronning Eufemias gate, one of Oslo's broadest avenues today, is named for her — unusually, for a queen rather than a king.
Older than the story we tell
Stand at the southern end of the park, near the old locomotive workshop built in 1890 directly over the buried remains of the king's castle, and the pattern of the whole walk becomes clear: almost everything known about medieval Oslo has surfaced by accident, as a side effect of building something else — a railway line in the 1800s, a tram tunnel more recently, a new manor extension whose excavation, in 2023, turned up a Viking boat grave nobody was looking for. Each round of infrastructure work has, so far, made the city's story a little older and a little stranger than the last one told. It is a reasonable bet that it isn't finished doing that yet.
Guide credit: Sara, Kulturetaten / Oslo Ladegård.