If you want to experience a snapshot of the many identities of Kaliningrad, the host of England’s final group match, it is enough to take a trip to the vacant, marshy island in the middle of the city.

In the centre of that island is the restored German cathedral, the final resting place of philosopher Immanuel Kant. There you experience the city’s past, its life as Königsberg, trading port and capital of East Prussia.

Look up and you see the city’s more overwhelming Soviet identity in the House of Soviets, an unmistakable brutalist structure. Built on the grounds of a 700-year-old castle, the building is known locally as “the monster” or “buried robot”.

To your left, you see checkpoints and security officers consistent with the region’s present status as a militarised exclave. And to your right, past the fishing village, is a new 35,000-seater £200m football stadium – a vision of shining modernity that authorities hope represents the city’s future.

Russia’s westernmost territory – nestling between Belarus, Lithuania and Poland – was handed to the Soviet Union as part of the Potsdam settlement. Then, its isolation was but a theoretical matter. Everyone, after all, was a happy comrade.

But after the fall of the Soviet empire, borders suddenly mattered. Kaliningrad found itself as an exclave, separated from “big Russia”, as the mainland is known locally, by 200 miles. Ever since then Kaliningrad has served as a weather vane of external relations – acting either as a bridge or a geopolitical bubble, depending on the Kremlin’s mood.

Away from the World Cup: the secret lives of goalposts in Russia Show all 28 1 /28 Away from the World Cup: the secret lives of goalposts in Russia Away from the World Cup: the secret lives of goalposts in Russia A boy hangs from a goalpost in St. Petersburg Reuters Away from the World Cup: the secret lives of goalposts in Russia Self-made goalposts stand on a soccer pitch in Verkhnyaya Biryusa village, located in the Taiga area near the Russian Siberian city of Krasnoyarsk Reuters Away from the World Cup: the secret lives of goalposts in Russia A boy rides a bicycle near a goalpost in Yevpatoria, Crimea Reuters Away from the World Cup: the secret lives of goalposts in Russia Hay fills a goalpost during the traditional Cossack games outside the village of Arkhonskaya in the Republic of North Ossetia, Alania Reuters Away from the World Cup: the secret lives of goalposts in Russia A car is seen through a goalpost while driving along a road in the Siberian village of Tyulkovo Reuters Away from the World Cup: the secret lives of goalposts in Russia Children play at a goalpost during the traditional Cossack games outside the village of Arkhonskaya in the Republic of North Ossetia, Alania Reuters Away from the World Cup: the secret lives of goalposts in Russia A goalpost stands in the village of Pribrezhnoye, Crimea Reuters Away from the World Cup: the secret lives of goalposts in Russia People and dogs walk near a goalpost on the Ostrov Otdykha (the Island of Rest), located in the middle of the Yenisei River Reuters Away from the World Cup: the secret lives of goalposts in Russia A boy rides a gyro-scooter near a goalpost on a football pitch in the Siberian town of Divnogorsk Reuters Away from the World Cup: the secret lives of goalposts in Russia Cossacks sit on a bench next to a goalpost covered with a screen during the traditional Cossack games outside the village of Arkhonskaya in the Republic of North Ossetia Reuters Away from the World Cup: the secret lives of goalposts in Russia A goalpost stands in front of an Orthodox church in the Siberian village of Tyulkovo Reuters Away from the World Cup: the secret lives of goalposts in Russia Goalposts lay on the ground as people gather at a flooded beach on the bank of the Volga River in Samara Reuters Away from the World Cup: the secret lives of goalposts in Russia A goalpost stands in Yevpatoria Reuters Away from the World Cup: the secret lives of goalposts in Russia A man sits on a goalpost in the settlement of Novo-Schedrinskaya, Chechnya Reuters Away from the World Cup: the secret lives of goalposts in Russia A participant is seen through a goalpost during an amateur football tournament at the Zenit Arena, a stadium made from straw, in Stravropol Reuters Away from the World Cup: the secret lives of goalposts in Russia A goalpost in a yard of a Stalin-era high-rise building in Moscow Reuters Away from the World Cup: the secret lives of goalposts in Russia Goats walk near a goalpost in the village of Pervomayskoye, Crimea Reuters Away from the World Cup: the secret lives of goalposts in Russia A goalpost stands at a tourist centre on the bank of the Belyo Lake in the Republic of Khakassia, Siberia Reuters Away from the World Cup: the secret lives of goalposts in Russia A goalpost stands in the town of Dolgoprudny in the Moscow region Reuters Away from the World Cup: the secret lives of goalposts in Russia A man runs near goalposts on a football pitch in a settlement in Stavropol region Reuters Away from the World Cup: the secret lives of goalposts in Russia A dog stands near a goalpost in Ryazantsevo settlement in Yaroslavl region Reuters Away from the World Cup: the secret lives of goalposts in Russia Children play with a puppy near a goalpost on a football pitch in the Siberian settlement of Novosyolovo Reuters Away from the World Cup: the secret lives of goalposts in Russia A goalpost stands in the village of Lesnovka, Saksky district, Crimea Reuters Away from the World Cup: the secret lives of goalposts in Russia A goalpost stands in the village of Zhuravli, Crimea Reuters Away from the World Cup: the secret lives of goalposts in Russia A man rides a horse near a goalpost in the village of Bolshaya Dzhalga in Stavropol region Reuters Away from the World Cup: the secret lives of goalposts in Russia A goalpost stands in Sevastopol, Crimea Reuters Away from the World Cup: the secret lives of goalposts in Russia A cadet holds a model of a sword in front of a goalpost as he trains at the stadium of the General Yermolov Cadet School in Stavropol Reuters Away from the World Cup: the secret lives of goalposts in Russia A goalpost stands in the village of Glinka, Saksky region, Crimea Reuters

In the 1990s, following nearly half a century as a closed armed garrison, the region transformed itself into Russia’s Hong Kong. European business made it their tax-free Russian home. In the early Putin years, issues over visa-free travel for locals were the harbinger of the larger impasse that would come.

Today, Kaliningrad has become an unforgiving mirror on east-west anxieties. It has become, in the words of Nato commander General Philip M Breedlove, a “very militarised piece of capital”.

The strategic importance of Kaliningrad comes down to two things, says Justin Bronk, a research fellow at the RUSI defence and security think tank based in London.

First, the exclave extends the range of Russia’s powerful anti-ship and anti-aircraft missiles significantly; now they cover much of Nato’s eastern territories in Poland and the Baltic states. Second, its position limits the capacity of Nato ground forces to defend the Baltic border by reducing the gap through which troops can move.

England fans celebrate after beating Tunisia in first game at Russia 2018 World Cup

In recent years, Russia has invested in a huge modernisation of Kaliningrad’s missile systems. It brought in nuclear-capable, dual-purpose Iskander-M systems to the region – temporarily, the Kremlin insists. There is evidence that Russia may be upgrading nuclear missile storage facilities.

Mr Bronk says the west is right to be concerned: “The Russians may insist the redeployment is temporary, but in the absence of inspections we have to assume the missiles remain.”

Even though that military standoff seems to be here for the long term, few locals are willing to contemplate a turn away from what they see as the region’s European roots.

While most of the region’s Germanic identity was destroyed either by RAF bombers or deliberate Soviet design, Kaliningrad is increasingly looking to embrace its European past. The new shopping centre in the centre of town, which offers an unusually wide range of western retail, is called, appropriately enough, Europa. Facades of Khrushchev-era prefab housing have been spruced up in German, gingerbread style in time for the World Cup.

At least some of the region’s newfound European identity is commerce driven, suggests the local historian Alexander Popadin.

“Königsberg is a better sell than Kaliningrad, basically,” he says. “Politics don’t always play a role”

In the Yeltsin bar, a hipster joint with kraftovoye beer and designer filament lightbulbs, talk of Iskanders certainly seems a world away. Tattooed barmen debate the attributes of the 19 beers on tap. A live band attempts to drown out the chanting of a small group of England fans, delirious at Germany’s early exit from the World Cup. There is talk of urbanism, Allen Ginsberg and quesadillas with guacamole.

Outside the bar, a plaque showing the 29th article of the Russian constitution spoke to the rebellious spirit of the people inside. “Everyone in this bar shall be guaranteed freedom of speech and expression,” it reads.