Their first steps are tentative as they emerge into the public eye for the first time.
To start with, these two polar bear cubs seem painfully shy, sheltered beneath the massive bulk of their mother, Olinka.
The three-month-old twin males, born in November at the Schoenbrunn Zoo in Vienna, come out and take turns to examine their strange new surroundings. Scroll down for more ...
Play-fighting: The twins wrestle as they explore their surroundings in Schoenbrunn Zoo
But slowly growing accustomed to this brave new world, it does not take long before the rocky outcrops and shale-like surroundings become a giant playpen.
Ignoring all onlookers, the twins soon bound about like veterans.
Climbing over rocks, tripping on the stairs or going nose to nose in a playful battle for supremacy, these cubs are little bundles of furry energy. Scroll down for more ...
Curious: One of the twins investigates a rubber tyre
Hopefully, they will avoid the fate of Knut, the cub at Berlin Zoo who captured the world's hearts after his mother spurned him and he was raised by humans.
Now, Knut is a disturbed and aggressive animal unable to forge links with other bears.
Likewise, at Nuremberg Zoo, two cubs had to be rescued after a third cub was eaten by its mother.
The Vienna pair should be more fortunate. Olinka has reared them carefully and watches over them as any mother would.
Dramatic paws: The battle for supremacy is on - at just three months of age
Polar bear twins enjoy their brave new world as mum looks on | the Daily Mail