Stockholm’s strategic Cold War stronghold

The BBC has an article by Amanda Ruggeri about Sweden and the Cold War:

Our ferry slid through the gunmetal-grey waters of the Baltic Sea. Granite outcroppings scattered around us, bald except for tufts of trees and the occasional bird; on the horizon, I could see only more rock, more sea, more mist. We were approaching the end of the Stockholm archipelago. It felt like we were approaching the ends of the Earth.
The Stockholm archipelago, Sweden’s largest, is made up of some thirty thousand islands that scatter east and south of the city, into the Baltic. Some of the islands are popular summer retreats, their shores thick with resort towns, souvenir shops and vacationing Swedes.
But I wasn’t headed to any of those. I was going to Öja, the archipelago’s southernmost island, home to one of the Cold War’s most advanced military batteries, which was off-limits to the public until January of 2013. Getting there requires riding the entire seventy kilometer length of a commuter rail line, switching to a twenty kilometer bus route through winding roads and thick forests, and taking a four kilometer ferry ride from Ankarudden harbor, on the island of Torö. It’s a journey that takes nearly three hours from central Stockholm.
At first glance, the four-kilometer-long, five-hundred-meter-wide island doesn’t seem worth the effort. It’s home to twenty year-round residents and a bird observatory. But Öja was also once home to a terrifyingly intricate system of nearly forty state-of-the-art military installations that were buried, almost invisibly, across the length of the island, ready to defend Sweden from an attack. Today, five survive, including the elaborate Cold War battery that could hit a target over twenty kilometers away and withstand a nuclear blast five times the one that leveled Hiroshima.
Not that you’d have any idea from simply being on the island.
Our ferry squeezed into the harbor, looking so unlikely to fit that I braced myself for the sound of scraping metal. The lack of people on the shore made it easy to find Jaak Kriisa, an older man with a cheerful face and a firm handshake. Kriisa is the island’s resident military expert, former tank company commander, and, as he put it happily, “five percent of the island’s population”. With warm greetings, he helped me into his golf cart, one of the most convenient methods for getting around Öja, and off we went, rattling along the dirt road that serves as the island’s main artery.
Our first stop was the Cold War bunker known as the Landsort Battery. Tucked among boulders and bushes, an army-green cannon protruded from a hump of granite. Nearby, hidden between rocks, a camouflaged door lead into the earth. The site didn’t look like much, but Kriisa gestured to a map just outside. Like a rabbit warren, an entire world lay beneath our feet, running four stories down and eighteen meters deep. Finished in 1977 and used until the Cold War’s end in 1991, the battery was supported by a crew of 325 men as well as anti-aircraft artillery and machine guns that could shoot well beyond the horizon.
“This was the most advanced artillery in the world during the Cold War,” Kriisa told me, unlocking the door. Tours run regularly in high season, but it’s wise to email Kriisa directly to ensure English options before you visit.
Originally, there were six coastal batteries in Sweden, each equipped with three twelve-centimeter guns, all built to deter invasion during the Cold War. The Landsort Battery is the only one left.
Tiny Öja, it turns out, stands in a crucial location. It marks the entrance to several sea routes to Stockholm, making it a key point of defense for the nation. Despite Sweden’s neutrality in the Cold War, the country feared that, in the case of a US-Soviet conflict, the Soviets would roll across Europe from the east. So Sweden built a network of high-tech, expensive artilleries exactly like this one. “We know the battery was a success, because it was never used!” Kriisa said, chuckling.
A “hot war”, a conflict involving actual fighting, was a frightening prospect for everyone, including the neutral Swedes. At the time, twenty percent of the Swedish budget went to defense. (Today, it’s less than two percent.) The Landsort Battery alone cost six hundred million krona to build. The country had the world’s fourth-largest air force. And every building in Sweden with more than one family was ordered to build bomb shelters by law.
Kriisa and I went through two sets of doors, each with walls over a meter thick. The first, he said, was built to withstand the shock wave that would be caused by a nuclear blast. The second was to keep out the gas. A shower stood just inside, ready to rinse any soldiers unlucky enough to be exposed to the blast.
Down another level, we walked through the bathroom, the bunks and into the kitchen, where the walls glowed with 1970s shades of green and orange. Everything had been left just as it was in 1991. When I opened one of the cabinets, I found an ancient jar of coffee, its grounds fossilized into a single chunk.
Heading back up to the top level, we paused in the artillery room. Ammunition sat stacked against a wall, ready to be loaded into the gun dock. Following Kriisa, I squeezed through a small door and looked up: a metal ladder ascended another story high, up into the tower that held the cannon I’d seen from outside. Hand over hand, I climbed.
Sitting next to one of the largest guns I’d likely ever see up close, legs swinging, I marvelled at little Öja’s chutzpah and at how hidden the island’s defenses were.
Later, I borrowed a creaky bike from Kriisa and pedalled to the island’s southern tip. The Landsort Lighthouse (photo), the largest in the archipelago and the oldest in Sweden, loomed above me, blinking green at ships in the distance. A cannon aimed south; behind it sat a cement pillbox. On the rocky shoreline far below, two other cannons sat alert. Öja’s first defense installation, built in 1933, this artillery and bunker was used during World War Two, in the same way the Cold War battery would later be used: as deterrence. It, too, never saw action. The Landsort Battery replaced it in the 1970s and was decommissioned in 2009.
Circling the lighthouse, heading inland, I stepped carefully along granite boulders, admiring the wild coastline, its rocks dotted with little red houses. Some thirty meters away from the pillbox, I looked down and paused. There were metal bolts beneath my feet. I was walking on a bunker, and I hadn’t even noticed.
By helping to deter both the Axis powers and the Soviets, Öja had helped win two wars for Sweden. By now, I realised, I should not be surprised by what I might find on this tiny, rocky islet in the Baltic Sea.

Rico says that, when he was in Sweden in the late 1960s, this was all still a state secret...