So a man rode a Boris bike along the edge of London Bridge during last Friday's morning rush hour.
London Bridge stands about 29 feet (almost 9 metres) above the river Thames. The rail the man was cycling across is only a few inches wide.
Luckily the rider didn't fall in. It looks as though he was buzzed by a drone, too.
Commuters crossing the bridge on foot seemed baffled.
The rider was identified as freerunner Tim Shieff, who had also performed some bike stunts on the rooftops of Regent Street the day before.
Shieff told London24 that the stunt was meant to shake viewers out of their everyday mindset.
“You don't worry about your issues for a second, you say: ‘Woah did that guy really just jump that on a big blue bike?’"
The London Bridge and Regent Street bike exercises were part of an urban sports series by Tim Shieff and fellow freerunner, Paul Joseph, who were filming for Fightme.com.