Two brothers are cycling 5,000 miles around Britain on tall bikes, which are made by stacking the frame of one bicycle on top of another.
The tall bikes are made from fixing one bicycle frame to another
Will, 25, and 24-year-old Ed Stevens began their charity venture on 1 April.
The pair are in Orkney and intend to appear at the Halkirk Games in Caithness on Saturday.
According to the brothers, tall bikes originated in the 19th Century and were used by fruit pickers and for training British soldiers to race camels.
Will, who studied sculpture at art school in Oxford, said he had spent the past 18 months working as a bike messenger in Montreal.
Ed taught English for 12 months in Honduras.
Their latest venture is raising money for Charities Aid Foundation.
They have a website with pictures and regular updates from their Tall Bike Tour of Britain.
According to their site, tall bikes started out as a means for lamplighters to reach street lamps in Chicago.
Fruit pickers in Catalonia used them and British colonial troops rode elevated bikes to train for camel races so they could compete with locals.