Deep beneath the earth of Ronneburg, under a radiant carpet of daffodils and yellow rape fields, lies one of the deadliest secrets of the Cold War: the uranium mine that supplied the Soviet nuclear arsenal.

From today this unhappy corner of eastern Germany becomes a tourist attraction with the Federal Garden Show 2007, expected to draw up to 1.5 million visitors. It features a newly planted meadow and landscape area scattered with art installations, including a flock of blue sheep.

The contrast could not be more stark. The region around Gera and Ronneburg, close to the Czech border, used to be dominated by slag heaps and a 1¼ (2km) hole. East Germany was the world’s largest producer of uranium: 231,000 tonnes were excavated, often at terrible human cost, and delivered to the Soviet Union. The local rivers were irradiated and, as miners died of lung cancer, those in the know began to call it the Valley of Death.

The Darmstadt Institute of Ecology has — to the relief of the garden show organisers — pronounced it safe. “There is no heightened risk entailed in visiting the gardens,” it concludes. “The radiation is not higher than that in other regions of Germany, and is equivalent to the natural uranium traces found in normal soil.”

So visitors will be able to admire 10,000 prize roses, 10,000 flowering shrubs, 1,000 yellow broom bushes, a parade of red tulips and 410 different trees from across the northern hemisphere. More than 280,000 bulbs have been planted.

The idea of a federal garden show began in the 1950s, when the West German Government laid lawns and herbaceous borders on the rubble of Kassel, a city hit hard in Allied bombings. Since then the Government, in effect, has created a new park every two years.

This time it is the Cold War that is being pushed under the flowerbeds, and for older locals the transition is stunning.

Klaus Hinke, a tourist guide, still remembers “when the villages were cleared of people so that the radioactive ore could be driven from Ronneburg through the streets to Gera railway station”.

Miners in Ronneburg were privileged. They were at the top of the waiting list for cars and colour TVs. They had their own Baltic Sea complex — the authorities did not want them to mix with other workers — and their own centrally heated flats in Gera.

Each miner was also allocated eight litres of schnapps a month — nicknamed Kumpeltod (mate’s death). It was drunk to blot out the memory of fellow miners who died by breathing in radioactive gases or in hushed-up accidents.

At least 5,000, but perhaps as many as 17,000, died as a result of radiation; many thousands became impotent. Their children, who played on the slag heaps, have been dying early.

The project was run by the Soviet-German company Wismut, which sponsored football teams, schools and, more importantly, hospitals: it was regarded as a priority that East Germans did not get wind of the high physical cost of delivering uranium to Moscow.

Filling in the holes, disposing of the 48 vast slag heaps and sealing the mines with concrete has cost several billion euros. With tickets priced at €16 (£11) — expensive for an ailing corner of Germany — the flower show is unlikely to gemerate a profit. But the Government’s aim is to convince Germans that the Valley of Death is a fertile place.

Park life

— People evacuated the Chernobyl exclusion zone in 1986. It now hosts species unseen for decades, such as the lynx and the eagle owl

— Mill Ends Park in Portland, Oregon, is the smallest park in the world. It is 2ft wide and its creator claimed it was meant to be a colony for leprechauns

— A coal refinery makes an unusual focal point at the Gas Works Park in Seattle. The disused towers are surrounded by hills

— A military exercise area at the Israeli Defence Forces’ northern command has become a retirement home for elderly zoo animals

Sources: portlandonline.com; Times archives

Times Recommends

• The Japanese Prime Minister is doomed: or is he?
• Brighton company 'involved in cyber attack'
• The art of survival: it’s all in the mind