From Nazi bunker to hipster hub

It’s not often I get to stay in a city hotel bristling with lightning conductors for fear of forest fire. Or in whose eighth floor room I feel impelled to draw the curtains, lest I provide involuntary entertainment for abseiling gardeners, or for passers-by on a so-called “mountain path”.

But this remarkable new hotel in Hamburg, veiled as it is with elaborate hanging gardens, is unlike any other — both a model of sustainability and an uncomfortable lump of war history. Finally opened on July 5, two years behind schedule, the new foliage-clad part squats atop a giant Nazi bunker, built in 1942 by a thousand slave labourers. Originally 38 metres tall, and with steel-reinforced concrete walls 3.5 metres thick, it was judged too big to knock down, and has endured as the most brutal of brutalist landmarks.

It’s a bold move to open a hotel in a challenging property like this, but in recent years Germany has led the way in repurposing difficult structures. The spectacular tangle of metal and steel that was the Völklingen Ironworks is now partly a music venue; a massive blast furnace in Duisburg now hosts a cinema; and the giant gasometer in Oberhausen has become an art gallery.

They do it for hotels, too. Here in Hamburg there are already two examples: the Mövenpick in a former water tower, and the sophisticated Westin at the Elbphilharmonie, housed in a magnificent glass wave created atop a former tobacco warehouse in the reborn HafenCity docks area. The latter, known locally as the Elphi, was controversial for delays and a huge budget overrun, but has since become such a successful national symbol that it was the venue for the draw for the Euro 2024 football tournament.

But the Hamburg Bunker is in another league. Originally known as Flakturm IV, it was one of eight vast flak towers built across Germany in response to RAF air-raids on Berlin in 1940. Hamburg, with its key role in oil production, ship and submarine building, was an obvious target. The towers had anti-aircraft guns on the roof, while the buildings themselves acted as civilian air-raid shelters; Flakturm IV was designed to accommodate 18,000 people, though was sometimes used by many more.

Now visitors are being encouraged to “experience the magic of this historic place” in an unlikely €100mn reinvention as what the tourist board is touting as a new cultural and gastronomic hub for the city, with four restaurants, roof terraces and a concert hall, as well as the hotel.

The relaunched bunker has strong parallels with its waterside cousin, the Elphi, not just because each looks askance at the other across the city’s rooftops. For both, the hotel part is in a new installation created on top of a historic structure. Both buildings have concert halls at their heart, and both have freely accessed public spaces as part of their offering.

But instead of the Elphi’s glass wave this new hotel is shrouded in green. The five new floors added above the old concrete edifice have been planted with 4,700 trees and shrubs and 13,000 other plants, albeit most still in their initial stages of growth. At the top, almost 60 metres above the surrounding pavements, is a patch of lawn with a little apple orchard, a green hideaway reached via that 560 metre-long “mountain path” — metal stairs and walkways that wind up from ground level around the building’s circumference.

The tree-sheltered top is the highest freely accessible public space in Hamburg. Thus the lightning conductors — and the security guards, to ensure no one unrolls their beach towel and takes up residence on the lawn on sunny days.

Like the Elphi, the transitional layer where the old building ends and the new begins — here designated as floor zero — is open to the public. The four former gun emplacements now house a restaurant and bar, a café, a shop and the foyer for the hotel, Reverb, part of the Hard Rock chain, which, together with the 2,000-seater concert auditorium, fills the floors above. (Even here there’s community access, though, with the performance space doubling as a sports hall for local schools, its innovative LED floor lighting up with white stripes depending on which sport is being played.)

The location, too, is a bit of an adventure. Unlike the Elphi, which has a ready supply of tourists in HafenCity, the bunker is embedded in St Pauli, a working class district of Hamburg, next to a former slaughterhouse now repurposed as a food emporium. Here it broods over the Heiligengeistfeld, an open space used for funfairs and big outdoor events, and dominates views from the Millerntor stadium of the famously socialist and community-engaged St Pauli football club, which provides support for refugees, the homeless and even honeybees.

More than 600 other bunkers still exist in Hamburg, albeit smaller and mostly partially underground or hidden behind residential buildings, blending into the cityscape. Over the decades, even the intimidating Flakturm IV has become an accepted feature of local life, the interior spaces of the original building being used by tenants including picture framers, a music shop and school, radio studios and media start-ups.

Little of the building’s darker past is acknowledged in its new incarnation as yet, although there are plans for a memorial to the victims of the Nazi regime, including the labourers who built the tower in just 300 days. Most came from Hamburg’s fearsome Neuengamme concentration camp, where inmates including socialists, homosexuals and Russians were only expected to survive three months.

There were also civilian deaths in the tower, explains cultural historian Tomas Kaiser, one of the team preparing guided tours of the site. He points out the handful of information panels on floor zero, and then takes me down inside the bunker and shows me the spiral staircases that originally had no railings because of iron shortages, the cause of fatal accidents as people rushed in to take shelter.

Among the current crop of tenants in the cavernous interior is a boxing gym, a nightclub, a media training centre and an innovative rehearsal room cum performance space for a democratically run (ie conductor-less) chamber orchestra. In short, creative, young, musical — and very reflective of the streets outside.

“It’s a new Berlin”, says Kaiser, as he takes me out past vinyl and vintage shops on Marktstrasse, stopping briefly to admire one place that upcycles oil barrels from Hamburg harbour into furniture. “Berlin itself has become so full of foreigners, so expensive. Artists and musicians are coming here instead,” he says.

He’s right, the neighbourhood does look similar to how Prenzlauer Berg or Kreuzberg, the hipster districts of Berlin, looked 20 years ago. Kaiser walks me past community housing co-operatives and impromptu flea markets, every doorway covered in street art and left-leaning slogans. Little social gatherings are taking place in tea houses and on street corners, often around an open bottle of wine. “We call it cornering,” says Kaiser, cutting through a leafy courtyard to where another much smaller bunker stands, now a climbing wall.

He avoids the Reeperbahn, the red-light district thick with dive bars, cabarets and music venues, but he is enthusiastic about the annual Reeperbahn music festival. Once upon a time — starting with The Beatles era — Hamburg was the source of 80 per cent of German music, until Berlin took over. Now, he says, the trend is for musicians to return.

It is that passion for music that the Reverb hotel is trying to tap into. Its 134 guest rooms are industrial chic in style, with exposed pipework and brushed concrete wet-rooms, allied to colourful music-themed decor. In addition to the concert hall programme, the Reverb has an ambitious live music schedule both in its bar and its restaurant, and some rooms are set aside for visiting artists.

The whole enterprise is the creation of Hamburg entrepreneur Professor Thomas Matzen, who took on the 99-year lease for the bunker back in 1993. In 2019, the initial budget for the new floors and gardens was €35mn; a figure that has escalated to €100mn, according to the hotel management.

Matzen, now in his seventies, has acknowledged that his investment is not going to provide a return in his lifetime. But even as the foliage begins to grow and soften the building’s sharp concrete corners, it’s clear he has created a new destination for the city.

My own visit to the bunker coincided with last weekend’s Euro 2024 quarter-finals, when Portugal were playing France in Hamburg. With the raucous fan zone sprawled across the Heiligengeistfeld, the bunker’s management had closed off the rooftop to all but the hotel’s guests. Most of those were elsewhere watching the game, and as it went to penalties and the sun began to set, I had the roof almost to myself, sitting quietly on the lawn amid mountain pines, junipers and rose bushes — where once the anti-aircraft guns roared, now the unlikeliest of oases.

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