Like prisoners emerging from a lifetime behind bars, a group of chimpanzees step blinking into the sunlight. This is the first time they have felt grass under their feet and breathed fresh air for 30 years.
Some of the chimps were born in captivity but most were kidnapped from African jungles and sent to Europe, where they were locked in metal laboratory cages to be used in a long series of experiments.
Their ordeal finally ended in September 2011 when 38 of the surviving chimps were released into a sanctuary in Austria called Gut Aiderbichl, allowing them to feel the nurturing contact of their fellow chimps after years of being separated by bars and bullet-proof glass.
The celebratory moment between the chimps at 1:25 seconds will break your heart.