Sealed off by grey concrete walls and barbed wire, the workmen in protective glasses and steel-toed boots at this smelter cannot work fast enough to meet demand from the nervous rich for gold.
This refinery near Lake Lugano in the Alps is running day and night as people worried about recession rush to switch their assets into something that may hold its value.
"I have been in the gold business for 30 years and I have never experienced anything like this," said Bernhard Schnellmann, director for precious metal services at the refiner Argor-Heraeus, one of the world's three largest.
"Production has dramatically increased since the middle of the year. We cannot cope with demand," said Mr Schnellman, wearing a gold watch on his wrist.
The trigger for the price to rise again could come from a much weaker dollar, making gold cheaper for holders of other currencies, and a renewed aversion to paper assets as governments and central banks pump large amounts of cash into the economy, stoking inflation.
Though Switzerland is not a gold miner, it is home to some of the world's largest refineries, which process an estimated 40 per cent of all newly-mined gold.
Argor-Heraeus is part-owned by the Austrian Mint and a subsidiary of Germany's Commerzbank. Commercial and central banks are its chief customers and it says it processes some 350-400 tonnes of gold and 350 tonnes of silver per year.
Customers buying gold bars, which can weigh more than 10 kilos each, have to wait roughly a month, taking into account the year-end holiday season. For those buying coins or ingots, which can fit into the palm of a hand, the delay is six to eight weeks. A year ago, these small products could be had within a couple of days.
Worries about the banking system globally have boosted worldwide demand for physical gold, the Gold Council said. "Many (people) are afraid of leaving their money in banks," said Sandra Conway, managing director at ATS Bullion in London, which sells bullion and gold coins to institutions and the retail market.
Other Swiss gold refiners also say business is booming.
"Since the summer we have experienced a sharp rise in demand for certain gold products. The one-kilo bar has become very popular," said Fiorenzo Arbini, in charge of health and safety at Pamp, another large Swiss refiner.
"People used to buy certificates, now they want physical gold."
Gold refiners were established in Switzerland to supply the watch industry and, later, jewellery-makers in Italy.
Switzerland's largest banks stepped in to replace a void in gold trading while the London gold market was shut after World War II and again during a brief closure in 1968.
The former Soviet Union, another top gold producer, chose Zurich banks to handle most of its gold sales in the 1970s and 1980s.
"Gold has an image of being the asset of last resort. This could be viewed as old-fashioned but this is how enough people with enough money to matter think," said Stephen Briggs, a metals strategist at RBS Global Banking & Markets.
India, China and the Middle East remain the biggest gold importers, particularly for jewellery. But demand for physical gold has exploded also in Europe, the Gold Council said.
In Switzerland, home to the world's largest private banking industry, demand for gold bars and coins shot up six-fold to 21 tonnes in the third quarter of this year, more than in any other European country.