But that is where the artwork of Nelson Mandela is hanging, inspired by his time in South Africa's most notorious prison.
The face of the man regarded by millions as the world's greatest living statesman - the secular world's equivalent of the Pope - looks out from the tiny Belgravia Gallery over a row of immaculate and extremely expensive Georgian houses.
It is an irony Mandela would no doubt appreciate...
Each of the sketches - executed by Mandela earlier this year to raise money for children and HIV victims through his trust - has a run of 500 signed lithographs, and for many people the signature alone will persuade them to part with thousands.
But the lithograph prints will not fulfil expectations.
Those anticipating dark reminiscences of a dark place will be surprised to see that Mandela's vision of the place where he spent much of his 27 years imprisonment is brilliant and luminous.
Mandela's sketches are the exact opposite of what one would expect of somebody incarcerated, far from friends and at the mercy of cruel warders.