Six cyclists have ridden London's deepest bike ride nearly 200ft underground – inside a 'super sewer'.
The keen cyclists got the experience underneath the capital as part of a charity fundraiser before the sewer becomes operational.
The 2.8 mile sewer began construction in 2016 and is due to be completed in 2025. When finished, it will remove 95% of around 40 million tonnes of raw sewage that currently spills into the River Thames every year.
It sits between 40 metres and 50 metres under the surface, making it deeper than any of the tube lines in the capital.
Employees working on the project at Tideway London were offered the opportunity to buy raffle tickets to win the chance to take their bikes down into the depths, raising £1,535 in total for charity.
The lucky winners made their descent at Battersea then cycled uphill through the sewer – whose deepest point hits 66m below ground level – to Blackfriars and back.
Taylor Geall, media relations manager at Tideway London, said: "The event went really well and everyone had a really good time. It’s a once in a lifetime experience."
The tunnel, which is budgeted at £4.4bn, is being paid for by Thames Water customers, who pay between £20 and £25 each year for the project.
Geall said: "There has been a desire for many years to clean up the river.
"The sewer system in London is 150 years old and is miraculously still in a really good condition but it just can’t cope with the modern day population of London.
"A lot of analysis was done in the 90s to find out what the best solution would be and this super sewer was chosen as the quickest most cost effective way of cleaning up the Thames."
The money raised by the raffle will go to Time & Talents, a community centre in London, and the Felix Project, which saves surplus food and distributes it to charities that help those in need.