🇸🇪 Sweden · Baltic islands
Kalmar is one of those Swedish cities that combine history, water and human-scale charm to perfection. It sits on the country's southeast coast, in Småland, facing the island of Öland, and its great treasure is Kalmar castle (Kalmar slott): a Renaissance fortress of round towers, moat and battlements that is reflected in the water and is considered one of the best-preserved castles of its period in northern Europe. Seeing it at sunset, golden on its islet, is one of the loveliest sights in Sweden.
But Kalmar is much more than its castle. It has an old town (Gamla stan) of wooden houses and cobbled streets, an imposing baroque cathedral on its main square, a lively harbour and the fascinating museum of the Kronan, the warship that sank off Öland in 1676 and whose treasures — gold, cannons, everyday objects — were recovered from the seabed. And it has a central place in Scandinavian history: it was here, in 1397, that the Kalmar Union was sealed, bringing Sweden, Denmark and Norway under one crown.
This guide covers Kalmar with a practical and warm eye: what to see in the castle and in the city, how to slip over to Öland across the bridge, how to get there and get around, when to go and what everything costs (with the usual note about how expensive and cashless Sweden is). A perfect city for combining a storybook castle, Nordic history, the sea and an ideal base for exploring southeastern Sweden, including the sunny island next door and the Kingdom of Crystal.
Kalmar is one of the oldest cities in Sweden: already in the Middle Ages it was a first-rank port and stronghold, protected by a castle that defended the kingdom's southern border against Denmark. Its starring moment came in 1397, when the Kalmar Union was proclaimed here, joining the crowns of Sweden, Denmark and Norway under a single monarch, Queen Margaret I; the union would last, with tensions, more than a century. For centuries, Kalmar was a border and garrison town, fought over in the wars between Swedes and Danes (Scania and Blekinge, to the south, were Danish until 1658). In the sixteenth century, the kings of the Vasa house transformed the medieval castle into the splendid Renaissance palace you visit today. In 1647, a fire and new needs led to the city being moved and rebuilt on the island of Kvarnholmen, where the centre is today, with its baroque cathedral. The full story is on our history page.
Read the full history ↓The great islands of the Swedish Baltic: Gotland, with the walled medieval Visby of the Hanseatic League and the tragedy of 1361; sunny Öland, of Iron Age forts, windmills and steppe; and Kalmar, whose castle saw the birth of the union of the three Scandinavian kingdoms.
Read the history of Baltic islands →No exact prices: a scale from $ (budget) to $$$$$ (luxury), with 2-3 options per category.
Origins, formation and what the sources say.
Kalmar is one of the oldest cities in Sweden, and for centuries it was one of the most important. Its origin goes back to the early Middle Ages, when at this point on the southeast coast, facing the island of Öland, there was a port and a market place that made the most of a strategic position: here, in the Kalmar strait, the Baltic sea routes passed, and here lay the southern border of the Swedish kingdom facing the Danish lands of Scania and Blekinge, which reached almost to the city.
That border status explains almost everything. To defend the kingdom's edge, as early as the twelfth century a defensive tower was raised at Kalmar beside the water, which over the Middle Ages grew into a powerful castle, one of the strongest in Scandinavia. The medieval town developed under the shelter of that fortress, and became an important trading centre, with contacts with the Hanseatic League and with the whole Baltic region. Kalmar had a friary, churches, walls and a busy harbour.
It was said that Kalmar was, along with Stockholm, one of the 'keys to the kingdom': whoever controlled its castle controlled the southern access to Sweden. That is why the city and its fortress were the constant setting for treaties, royal weddings, sieges and conflicts. Kings and nobles met here to negotiate peace or prepare for war, and the castle walls saw a good part of medieval Scandinavian high politics pass by.
In that context of border, trade and power, Kalmar was to take the leading role in one of the most important events in the history of northern Europe: the union of the three Scandinavian crowns under a single sceptre.
The name of Kalmar was engraved forever in European history by an event that took place in 1397: the Kalmar Union. That year, in this city and in its castle, a pact was sealed that joined the three Scandinavian crowns — Sweden (which then included Finland), Denmark and Norway (with its territories of Iceland, Greenland and the northern islands) — under a single monarch. It was one of the largest states in the Europe of its time by area.
The great architect of the union was Queen Margaret I of Denmark, one of the most skilful rulers of the Middle Ages. After inheriting and accumulating power in the three kingdoms, Margaret secured recognition of her great-nephew Eric of Pomerania as common sovereign, crowned king of the three kingdoms at Kalmar in 1397, although real power stayed in Margaret's hands until her death in 1412. The idea was to create a strong Scandinavian bloc, able to resist the pressure of the German Hanseatic League, which dominated Baltic trade.
The Kalmar Union lasted, with tensions and ruptures, more than a century, until 1523. But it was never a harmonious fusion: the interests of Swedes, Danes and Norwegians often clashed, and above all the Swedish nobility resisted Danish dominance. There were risings, internal wars and moments of breakdown. The bloodiest was the 'Stockholm Bloodbath' of 1520, when the Danish king Christian II executed dozens of Swedish nobles and notables, an act that set off the final rebellion.
That rebellion, led by the young nobleman Gustav Vasa, ended the Union: in 1523, Sweden broke away and Gustav Vasa was proclaimed king, founding the modern Swedish state. The Kalmar Union, born in this city, was broken, but its memory endures as one of the great 'what ifs' of Scandinavian history. Even today the three crowns (Tre Kronor) are Sweden's national symbol.
With the founding of the modern Swedish state by Gustav Vasa (king from 1523 to 1560), Kalmar and its castle entered a new era. Gustav Vasa, obsessed with the defence of the kingdom and with modernising its fortresses, ordered the old medieval castle of Kalmar to be strengthened against the new firearms: thick walls, round bastions and defences adapted to artillery were built. Kalmar was still the 'key' to the south, more necessary than ever in the endless wars with Denmark.
But it was Gustav Vasa's sons — kings Erik XIV (1560-1568) and Johan III (1568-1592) — who transformed the fortress into the splendid Renaissance palace we admire today. Influenced by European court fashions, they commissioned a remodelling that turned the castle's interior into a refined royal residence: rooms decorated with wooden panelling, coffered ceilings, ornate fireplaces, portraits and details of great sophistication, such as the famous golden hall or King Erik XIV's bedroom. The exterior kept its defensive look, with the round towers topped by elegant domes.
The result is an extraordinary rarity: a castle that combines, as few in northern Europe do, the military strength of a border fortress with the beauty of a Renaissance palace. That it has been preserved so well — unlike so many castles that fell into ruin or were demolished — makes it one of Sweden's great architectural treasures.
During these centuries, Kalmar remained a contested stronghold. In the Kalmar War (1611-1613), a direct conflict between Sweden and Denmark, the city and the castle were besieged and taken by the Danes before returning to Swedish hands. The border with Denmark was still dangerously close, and Kalmar remained on the front line.
The seventeenth century brought Kalmar two episodes that shaped its appearance and its memory. The first was the moving of the city. Old medieval Kalmar was crammed beside the castle, in a vulnerable and by now inadequate spot. After several fires and for defensive reasons — in the middle of the age of the Nordic wars — it was decided to move and rebuild the city on the neighbouring island of Kvarnholmen, better protected. The move was carried out from 1647, and there a new city arose, planned according to seventeenth-century canons: a grid of streets, walls and bastions, and at the centre a great baroque cathedral designed by Nicodemus Tessin the Elder, whose construction began in 1660. Old Kalmar was left behind, reduced to the quarter of wooden houses that is today Gamla stan.
The second episode was a maritime tragedy that echoed across the kingdom: the sinking of the Kronan. On 1 June 1676, during the Scanian War, the Swedish fleet faced the Danish and Dutch navies off the east coast of Öland, not far from Kalmar. The Kronan, flagship of the navy and one of the largest warships in the world, with more than a hundred cannons, made a sharp manoeuvre, heeled too far, took on water through the gun ports and suffered an explosion in the powder magazine that sank it within minutes. Some 800 men died; barely a few dozen were saved. It was one of the greatest naval catastrophes in Swedish history.
The wreck lay on the bottom of the Baltic, forgotten, for more than three centuries, until it was located in 1980. Since then, decades of underwater excavations have recovered an incredible treasure: bronze cannons, gold coins, navigation instruments, clothing, tools and objects of everyday life on board, preserved by the mud of the seabed. All of it is displayed today at the Kalmar läns museum, turning the tragedy of 1676 into one of the city's greatest attractions and a time capsule of the seventeenth century.
With the transfer of Scania, Blekinge and Halland to Sweden in 1658 (Treaty of Roskilde), the border finally moved away from Kalmar, and the city gradually lost its front-line military role, though it kept its castle, its harbour and its history.
On losing its status as a border city after the Danish frontier receded in 1658, Kalmar slowly turned into what it is today: a medium-sized historic city, quiet and pleasant, living off its heritage, its university, its harbour and its role as regional capital of southeastern Sweden. Over the eighteenth and nineteenth centuries it established itself as the administrative and commercial centre of the province, with its port life and its industry.
The twentieth and twenty-first centuries brought important changes. Kalmar developed its character as a university city — today it is part of Linköping University and previously it had its own institution, with a strong student presence — and bet on cultural tourism, resting on its castle, its historic centre and the Kronan museum. The restoration and promotion of the castle made it one of the most visited monuments in the country.
The milestone that changed the region's life most was the opening, in 1972, of the Öland bridge (Ölandsbron), which joins Kalmar with the island of Öland over more than six kilometres. The bridge, at the time the longest in Europe, integrated the sunny island with the mainland and made Kalmar the natural gateway to one of Sweden's great summer destinations. Every summer, thousands of holidaymakers pass through Kalmar on their way to the beaches, the windmills and the landscapes of Öland.
Today Kalmar combines, in a setting of water and Baltic light, several layers of history: the Renaissance castle on its islet, the wooden quarter of old Kalmar, the planned seventeenth-century city on Kvarnholmen with its baroque cathedral, and the memory of the Union of 1397 and of the Kronan tragedy. It is a city that carries its enormous past with ease, and that serves as a perfect base for exploring southeastern Sweden, the island of Öland and the neighbouring Kingdom of Crystal in Småland. One of those cities where the history of all Scandinavia can be touched with your hand.