For nearly two decades, Feti Gjici worked on a project that was so secret he was made to lock the plans away in a safe before leaving his office each evening. He never spoke of it to his friends or family.

Gjici was the chief planner of the town of Kukës, in northern Albania, working during the years of the country’s communist regime, led by the Stalinist dictator Enver Hoxha. The paranoid and isolationist leader was terrified of impending war and built hundreds of thousands of concrete bunkers to defend his population against the threat of invasion.

In Kukës, not far from the border with socialist Yugoslavia, things were taken a step further. Gjici’s task, beginning in the early 1970s and ending only with the collapse of the regime in 1991, was to build an underground replica of Kukës 30 metres below the overground town.

The first plans, in the early 1970s, were for a series of bomb shelters. As the 1980s went on, on the orders of army bosses, Gjici added ever more tunnels and rooms to the subterranean project, including space for a printing press, a hospital and a bakery. Then, electricity and water networks were added. There was to be an army command centre, a police point and a courtroom. The idea was that 10,000 people should be able to live self-sufficiently underground for a period of up to six months.

“Of course, in a time of war, things might run at reduced capacity, but the idea was to replicate the entire city underground,” recalled Gjici, now 72.

In the early 1970s, the communist authorities flooded the entire settlement of Kukës with an artificial lake during the construction of a hydroelectric plant. City planners had to design a brand new town alongside it, and resettled the whole population. Gjici was helping to design the second Kukës above ground when army and secret police bosses approached him. “Since I was doing a good job, they entrusted me with the plans for the underground town,” he said.

The Fierza reservoir and Drin river in Kukës. Photograph: Westend61 GmbH/Alamy Stock Photo

Asked what he would say if a colleague enquired as to what he was working on, he laughed. “It was not a culture where people asked you what you were doing.” His wife was vaguely aware he was working on a subterranean project for many years, but she too never demanded details. “She knew better than to ask questions.”

Because the shelter was so secret, Gjici had a team of just 30 construction workers to build it, as each worker had to be thoroughly vetted by the security services for political reliability. “The fewer people who knew, the better,” he said. This small team was further split into pairs who were sent to work on different parts of the shelter, not realising there was one huge interconnected network.

During the 1980s, the authorities carried out regular drills: when the siren sounded, the entire population of Kukës could get underground in seven minutes, through 30 entrances to the network. But it was forbidden to move around once below ground, and it was classified information that the whole network was joined together with tunnels that stretched for miles.

Feti Gjici in one of the tunnels. Photograph: Antonio Çakshiri

Construction on the underground network was completed in 1989 and electricity and water were installed. But before each of the areas could be properly equipped for its planned function, the regime fell.

These days, descending into the tunnels is not for the faint-hearted. The still spritely Gjici leads the way down a dank, cobwebbed stairway deeper and deeper underground. Access to most of the network of tunnels and rooms is blocked by huge piles of sand and mud.

But after 30 years of neglect, the new mayor of Kukës, Safet Gjici, Feti’s cousin, wants to finish what the communists started and complete work on underground Kukës before opening it to the public.

In the 1990s he was curious after hearing his cousin’s stories and descended into the abandoned network with some friends. “I’ll be honest, I couldn’t believe how deep it was,” he said in an interview at the mayor’s office. “We went some way in but I got terrified and turned back. There were rumours of people who went down there and never came back again.”

Later he visited again, this time with his cousin and proper lamps, and he could not believe how big it was. A grandiose vision began to form. Then a few months ago he was elected mayor and he decided it was time to act on it.

Modern Kukës. Photograph: Shaun Walker/The Guardian

“We want to turn it into an underground city for locals and tourists,” he said. He admitted his ideas were still vague, but he envisioned restaurants, attractions and shops, and people would be able to travel through the tunnels to exits at the artificial lake and then go pleasure-boating.

In March he hopes to finalise a deal for €2.6m of EU funding to begin renovations. But without much more money than that, his ambitious plans may be just as implausible as those of communist Albania.

There are also those who question turning the country’s communist heritage into theme park-style attractions. The vast complex of bunkers built for the elite on the outskirts of the capital, Tirana, has already been turned into a museum. There are plans to open Hoxha’s house, left exactly as it was when the dictator died in 1985, to the public.

“In the rest of communist Europe, the repressions finished in the 1960s, but here they went on right to the end,” said Enriketa Papa, a historian at the University of Tirana. “People were starving and they were still building bunkers. Why do we need museums of bunkers now, when there are no museums to the victims of communism?”

One of the Kukës tunnels. Photograph: Antonio Çakshiri

Safet Gjici was adamant that any underground museum would not gloss over the dark side of the communist years. “It was an awful time. Half the country were informers and there were limitations on everything. We don’t want to see those times again, not for ourselves and not for anyone else on earth,” he said.

His cousin was much more equivocal, reflecting a nostalgia for the Hoxha regime among a part of Albania’s older population, especially those who occupied privileged positions. “I was from a family of farmers in a village, and I was able to study engineering in the capital together with the son-in-law of Hoxha. Back then, there was no discrimination,” he said, glossing over the executions, labour camps and political prisoners.

As for the underground town, he dismissed the idea that its construction reflected a paranoid mindset and claimed it was the “absolute minimum” that any sensible government would provide for its citizens. “Now more than ever we need it,” he said. “It should be maintained, to teach younger generations that the risk of war is always there.”