Alain Robert, the free climber dubbed the "French Spiderman", scaled one of Barcelona's highest skyscrapers without a harness. And for the first time ever, the famous daredevil was joined by his son.
"This time is different. My son is not a climber so I feel responsible somehow," Robert told Reuters while preparing for the climb. "I know he's a big boy, 34. It's his own decision, but at the end of the day I am his dad."
Bystanders and Spanish police watched as the 60-year-old and his son, Julien, climbed the 144-metre Torre Glories, formerly the Torre Agbar, a glass-covered office building designed by architect Jean Nouvel and famed for its night-time illuminations.
"I feel very stressed. I've never been so scared in my life," Julien told Reuters just before they started.
"I've done scary things in life, but this is... I've never been so afraid for my life. Fortunately, I have my father who will talk to me, will guide me."
The pair completed the climb in less than an hour and were met at the top by police, who escorted them down the more traditional way - inside the building - and did not arrest them.
Julien, who spent eight years in the army and is a keen sportsman, prepared for his first climb by watching videos of his father's previous ascents.
Alain Robert began climbing in 1975, training on the cliffs near his hometown of Valence in southern France.
He took up solo climbing in 1977, since when he has climbed more than 150 buildings, including Dubai's Burj Khalifa - the world's tallest building - the Eiffel Tower, and San Francisco's Golden Gate Bridge.
Robert rarely gets permission and climbs without a harness, using only his bare hands, a pair of climbing shoes, and a bag of powdered chalk.