The gasometer was built in the late twenties to store gas generated as a byproduct of the processing of iron ore. The installation, which takes up almost all of its interior, has airlocks which allow visitors to go inside. The entire structure is self-supporting and kept aloft by two air fans.

The sculpture, known as “big air package,” is 90 metres high and has a diameter of 50 metres. It’s made from a semi-transparent polyester fabric as well as 4,500 meters of rope and weighs 5.3 tonnes.

Workers spent 2,800 hours preparing the 12.5 kilometre-long seams. The 600 sheets of fabric were fastened together by ropes and Velcro, to allow as little air as possible to escape.

Skylights illuminate the interior, mirroring the effect of stained glass windows inside a church and the trapped air muffles sound.

The website of Der Spiegel magazine described the experience of climbing the steps inside the sculpture as “floating upwards as if inside a surreal raincloud.”

The project has been in the works since 2010. Christo, who has spent much of his life collaborating with his wife, fellow artist Jeanne Claude, has included her in his work since her death.

He speaks of her as if she were still alive: “We are 77 now and I don’t know how much time we have left, so we’re trying to speed things up now by working on numerous projects simultaneously.” The couple made their first sculpture involving air in 1966.

The “big air package” will be on display until December 30, 2013.

The Local/kkf