Cyclists will be stripping off and pedalling through Cambridge this weekend.
The infamous event returns to the city for its fourth annual outing in Cambridge city centre as part of the World Naked Bike Ride (WNBR).
Dozens of naked cyclists descended on the city last year, as part of a number of WNBR events across the country.
But what on earth is at all about apart from being wild and free?
Here's what you need to know about the event:
What is the World Naked Bike Ride?
Its a series of events held around the world where naked cyclists hit the streets in a protest against car culture and to raise awareness of the vulnerability of cyclists.
In the UK, similar events are being held in Kent, Essex, London, Manchester and Scotland.
Where is it in Cambridge?
Last year's event started at Parker's Piece and took an eight mile circular route around the city centre.
But a change in organisers for this year's ride will see a new route introduced, starting from Midsummer Common.
When is it?
The next ride in Cambridge is due to take place on June 16, 2018.
World Naked Bike Ride
What are the rules?
Full nudity is optional – you can choose to take part naked, just wearing shorts, or even a swimming costume.
Will you be arrested?
No, it is legal to be naked in public in the UK as long as you are not doing it in a sexual context and with "the intention of causing distress, alarm or outrage”.
See the route of the 2018 Naked Bike Ride route here View fullscreen
How do you take part?
You can keep up to date via the event Facebook page.
What does the race organiser have to say?
Joe Fallowell said he was motivated to get involved in the event because of the environmental messages it supports.
"It's a lot of fun," he added. "Obviously the prospect of stripping off in public can be daunting for some people but it's a very supportive bunch of people."
Joe emphasised that people had a choice whether to take part naked or not.
"It's entirely about making people feel comfortable in their own skin," he explained.