This is the incredible moment a parkour yobbo leaps from a 20ft ledge above a busy city street on to the open-top sightseeing bus.
In the video - posted online - stunned onlookers can be seen gasping as the risky stunt is filmed from several angles.
The bus driver is then seen protesting with the young man who cleared the 8ft between the ledge and the bus, which was parked in Castle Meadow, unhurt.
Some of the man's friends cheer but the driver threatens to call the police.
The craze of jumping across city street furniture and climbing the sides of walls and buildings is known as parkour and has grown in popularity with the rise of young people posting videos on social media.
But the high-risk stunt has sparked anger from both Castle Quarter, which owns the land the man jumped from, and bus firm City Sightseeing Norwich.
A spokeswoman from Castle Quarter said: "We encourage all our visitors to act in a safe and sensible manner both inside our building and within the gardens and outdoor areas we share with the Castle Museum.
"There is no excuse for the behaviour shown in the Instagram video which puts both lives and property at risk."
The video on Instagram has 3,000 likes and more than 100 comments.
It was posted on Instagram account @tcole_sb on July 8.
A spokeswoman for City Sightseeing Norwich said: "The Norwich tour bus provides a fantastic service for tourists visiting the city as well as locals alike.
"This kind of behaviour by a very small minority is not only dangerous but damaging to the reputation of our city.
"When the bus is stationary at our Castle Meadow base we are always vigilant to try and avoid this kind of unacceptable behaviour."
A similar backlash came after a man filmed himself parachuting from the top of the crane outside Norwich Castle last summer.
It was labelled "a very serious and dangerous stunt" by Norfolk Museum Services.
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