A French daredevil known as the "Human Spider" brought traffic in a busy London neighborhood to a halt Thursday as he scaled the outside of a 46-floor skyscraper.

Alain Robert, 56, was arrested after scaling the outside of Heron Tower for "causing a public nuisance" and got a tongue lashing from local police who said the climber could have diverted first responders from "genuine emergencies."

"The incident this afternoon has had a considerable impact on police, other emergency services and the local community. Our officers, the London Fire Brigade and the London Ambulance Service all attended this incident taking them away from genuine emergencies," according to a statement from London police commander Karen Baxter.

French urban climber Alain Robert, also known as "Spider-Man," celebrates as he reaches the top of Heron Tower, the tallest tower in London, on Oct. 25, 2018. Daniel Leal-Olivas / AFP - Getty Images

About an hour before the climb, Roberts told Sky News that he scouted London for two days before picking the 755-foot-high Heron Tower for his dangerous climb.

It took him about 50 minutes to reach the top of his illegal climb, Sky reported.

“For me, it seems doable, meaning acceptable in terms of difficulties,” he told the British news network just before embarking on his challenge. “I just want to make sure I am not putting my life at risk.”

London police rushed to the neighborhood at about 1:30 p.m. local time (8:30 a.m. ET) and closed down several blocks around Heron Tower, also known as Sales Force Tower. Police declared all roads in reopened at 3:14 p.m. local time (10:14 a.m. ET).

The famed urban climber Robert, who only uses his bare hands and has no safety equipment, had also considered scaling the 525-foot-tall “Walkie-Talkie" tower on Fenchurch Street, or the 737-foot "Cheesegrater" on Leadenhall Street before settling on Heron Tower, he told Sky.

Heron Tower is the third tallest in London, behind only the 95-floor The Shard and 50-floor One Canada Square.

He's climbed other famous buildings such as Burj Khalifa in Dubai and the New York Times building in Manhattan.