The parents of a free-solo climber who scaled London's Shard unaided say it was "very wrong" for him to be jailed.
George King-Thompson was sentenced to six months in a young offenders institution for climbing the 310-metre (1,017ft) skyscraper, one of Europe's tallest buildings.
His parents Hilary and Clive said their son climbed to get a "message across to everyone to follow your passion".
The 20-year-old admitted being in contempt of court at the High Court.
After scaling The Shard, King-Thompson was given a police caution but the building's owners began legal proceedings against him for breaching an injunction.
Mrs King-Thompson said her son's punishment should have been "community service or to be tagged".
"He has got ADHD (attention deficit hyperactivity disorder). It's wrong to lock someone like that in a cell," she said.
"He climbs because he wants to get a message across to everyone to follow your passion. For him it is climbing to help mental health."
London Bridge Station was briefly closed when King-Thompson took 45 minutes to make the free-solo climb - without ropes or protective equipment - at about 05:00 BST on 8 July.
David Forsdick QC, representing Teighmore Construction Ltd, told the court that King-Thompson had been planning the climb for about eight months, including moving to east London and visiting the building up to 200 times "specifically to prepare" for it.
He said the 20-year-old "knew of The Shard injunction" and "recognised that the climb was illegal" by using the hashtag "rooftopillegal" when he posted a video of his efforts on Instagram.
Mr King-Thompson said his son's punishment was a "complete departure" from precedents set for other climbers in the past.
He said he did not think his son "understood the consequences" of scaling the building, which he added would be attempted by "very few people in the world".