Almost the whole pitch of the 32,000-capacity Woerthersee stadium, which hosted some of the fixtures of the Euro 2008 tournament, has been covered in 300 trees.
The arresting installation, entitled "For Forest", was unveiled to the media on Thursday before being opened to the public on Sunday for a few weeks of bucolic wandering. The transplanted forest is the brainchild of the Swiss artist Klaus Littmann who told reporters he wanted to create the image of "a forest that we have put in a totally new context".
"The contrast between the trees and the steel, concrete and glass -- you can't get better than that," Littmann said. Logistical challenges meant that bringing the vision into being was a "long and stony path", he said, adding that he had first suggested the project to city authorities six years ago.
"The moment that we're doing this in is uncanny," he said, pointing to the prominence that the climate crisis and the fires in the Amazon rainforest have gained in the media in recent months.
The installation has been supported by Klagenfurt's municipality and has been criticised by some as an extravagance. The 300 trees of various different kinds -- aspen, Oaks, birches and larches -- were grown in nurseries and will be moved out of the stadium on October 27.
As for Klagenfurt's football team, who play in Austria's Second League, it will temporarily move to a smaller facility nearby.